diff --git a/src/Battling/Models/CreateCreature.cpp b/src/Battling/Models/CreateCreature.cpp
index 1e58650..695aef6 100644
--- a/src/Battling/Models/CreateCreature.cpp
+++ b/src/Battling/Models/CreateCreature.cpp
@@ -5,8 +5,8 @@
 
 using namespace CreatureLib::Battling;
 
-CreateCreature* CreateCreature::WithVariant(std::string variant) {
-    this->_variant = std::move(variant);
+CreateCreature* CreateCreature::WithVariant(const Arbutils::CaseInsensitiveConstString& variant) {
+    this->_variant = variant;
     return this;
 }
 
@@ -20,18 +20,19 @@ CreateCreature* CreateCreature::WithGender(Library::Gender gender) {
     return this;
 }
 
-CreateCreature* CreateCreature::WithAttack(const std::string& attackName, AttackLearnMethod learnMethod) {
+CreateCreature* CreateCreature::WithAttack(const Arbutils::CaseInsensitiveConstString& attackName,
+                                           AttackLearnMethod learnMethod) {
     if (_attacks.size() >= _library->GetSettings()->GetMaximalMoves())
         throw CreatureException("You have already set the maximum amount of allowed moves.");
 
-    auto attackData = _library->GetAttackLibrary()->Get(attackName.c_str());
+    auto attackData = _library->GetAttackLibrary()->Get(attackName);
     _attacks.emplace_back(attackData, learnMethod);
     return this;
 }
 
 Creature* CreateCreature::Create() {
     auto rand = Arbutils::Random();
-    auto species = this->_library->GetSpeciesLibrary()->Get(this->_species.c_str());
+    auto species = this->_library->GetSpeciesLibrary()->Get(this->_species);
     auto variant = species->GetVariant(this->_variant);
     int8_t talent;
     if (this->_talent.empty()) {
@@ -48,8 +49,8 @@ Creature* CreateCreature::Create() {
         gender = species->GetRandomGender(rand);
     }
     const Library::Item* heldItem = nullptr;
-    if (!this->_heldItem.empty()) {
-        if (!_library->GetItemLibrary()->TryGet(this->_heldItem.c_str(), heldItem)) {
+    if (!this->_heldItem.Empty()) {
+        if (!_library->GetItemLibrary()->TryGet(this->_heldItem, heldItem)) {
             throw CreatureException("Invalid held item.");
         }
     }
diff --git a/src/Battling/Models/CreateCreature.hpp b/src/Battling/Models/CreateCreature.hpp
index ff7a274..a55943d 100644
--- a/src/Battling/Models/CreateCreature.hpp
+++ b/src/Battling/Models/CreateCreature.hpp
@@ -7,15 +7,15 @@
 namespace CreatureLib::Battling {
     class CreateCreature {
         const BattleLibrary* _library;
-        std::string _species;
-        std::string _variant = "default";
+        Arbutils::CaseInsensitiveConstString _species;
+        Arbutils::CaseInsensitiveConstString _variant = "default"_cnc;
         uint8_t _level;
         std::string _nickname = "";
 
         std::string _talent = "";
         Library::Gender _gender = static_cast<Library::Gender>(-1);
         uint8_t _coloring = 0;
-        std::string _heldItem = "";
+        Arbutils::CaseInsensitiveConstString _heldItem = ""_cnc;
         uint32_t _identifier = 0;
         std::vector<std::tuple<const Library::AttackData*, AttackLearnMethod>> _attacks = {};
 
@@ -23,10 +23,11 @@ namespace CreatureLib::Battling {
         CreateCreature(const BattleLibrary* library, std::string species, uint8_t level)
             : _library(library), _species(std::move(species)), _level(level) {}
 
-        CreateCreature* WithVariant(std::string variant);
+        CreateCreature* WithVariant(const Arbutils::CaseInsensitiveConstString& variant);
         CreateCreature* WithNickname(std::string nickname);
         CreateCreature* WithGender(Library::Gender gender);
-        CreateCreature* WithAttack(const std::string& attackName, AttackLearnMethod learnMethod);
+        CreateCreature* WithAttack(const Arbutils::CaseInsensitiveConstString& attackName,
+                                   AttackLearnMethod learnMethod);
 
         Creature* Create();
     };
diff --git a/src/Battling/Models/Creature.cpp b/src/Battling/Models/Creature.cpp
index d89cef4..14276bf 100644
--- a/src/Battling/Models/Creature.cpp
+++ b/src/Battling/Models/Creature.cpp
@@ -13,7 +13,11 @@ Battling::Creature::Creature(const BattleLibrary* library, const Library::Creatu
     : _library(library), _species(species), _variant(variant), _level(level), _experience(experience),
       _uniqueIdentifier(uid), _gender(gender), _coloring(coloring), _heldItem(heldItem), _nickname(std::move(nickname)),
       _talentIndex(talent), _hasOverridenTalent(false), _attacks(std::move(attacks)) {
+
     _activeTalent = _library->LoadScript(ScriptCategory::Talent, GetActiveTalent());
+    if (_nickname.empty()) {
+        _nickname = species->GetName().std_str();
+    }
 }
 
 void Battling::Creature::ChangeLevel(int8_t amount) {
@@ -21,12 +25,6 @@ void Battling::Creature::ChangeLevel(int8_t amount) {
     RecalculateFlatStats();
 }
 
-const std::string& Battling::Creature::GetNickname() const {
-    if (_nickname.empty())
-        return _species->GetName();
-    return _nickname;
-}
-
 const std::string& Battling::Creature::GetActiveTalent() const {
     if (_hasOverridenTalent) {
         return _overridenTalentName;
@@ -178,7 +176,7 @@ const Library::SpeciesVariant* Battling::Creature::GetDisplayVariant() const {
         variant = _variant;
     return variant;
 }
-void Battling::Creature::SetHeldItem(const std::string& itemName) {
+void Battling::Creature::SetHeldItem(const Arbutils::CaseInsensitiveConstString& itemName) {
     const Library::Item* item;
     if (!_library->GetItemLibrary()->TryGet(itemName, item)) {
         throw CreatureException("Item not found.");
diff --git a/src/Battling/Models/Creature.hpp b/src/Battling/Models/Creature.hpp
index 2df8012..2f96afb 100644
--- a/src/Battling/Models/Creature.hpp
+++ b/src/Battling/Models/Creature.hpp
@@ -86,7 +86,7 @@ namespace CreatureLib::Battling {
             return _heldItem != nullptr && _heldItem->GetName() == name;
         }
         inline const Library::Item* GetHeldItem() const { return _heldItem; }
-        void SetHeldItem(const std::string& itemName);
+        void SetHeldItem(const Arbutils::CaseInsensitiveConstString& itemName);
         inline void SetHeldItem(const Library::Item* item) { _heldItem = item; };
 
         inline uint32_t GetCurrentHealth() const { return _currentHealth; }
@@ -97,7 +97,7 @@ namespace CreatureLib::Battling {
         void SetOnBattleField(bool value) { _onBattleField = value; }
         bool IsOnBattleField() const { return _onBattleField; }
 
-        const std::string& GetNickname() const;
+        const std::string& GetNickname() const { return _nickname; }
         const std::string& GetActiveTalent() const;
 
         [[nodiscard]] bool IsFainted() const;
diff --git a/src/Library/Attacks/AttackData.cpp b/src/Library/Attacks/AttackData.cpp
index c860790..0483814 100644
--- a/src/Library/Attacks/AttackData.cpp
+++ b/src/Library/Attacks/AttackData.cpp
@@ -5,10 +5,10 @@ CreatureLib::Library::AttackData::AttackData(std::string name, uint8_t type,
                                              CreatureLib::Library::AttackCategory category, uint8_t power,
                                              uint8_t accuracy, uint8_t baseUsage,
                                              CreatureLib::Library::AttackTarget target, int8_t priority,
-                                             std::unordered_set<std::string> flags)
+                                             std::unordered_set<Arbutils::CaseInsensitiveConstString> flags)
     : _name(std::move(name)), _type(type), _category(category), _basePower(power), _accuracy(accuracy),
       _baseUsages(baseUsage), _target(target), _priority(priority), _flags(std::move(flags)) {}
 
-bool CreatureLib::Library::AttackData::HasFlag(const std::string& key) const {
+bool CreatureLib::Library::AttackData::HasFlag(const Arbutils::CaseInsensitiveConstString& key) const {
     return this->_flags.find(key) != this->_flags.end();
 }
diff --git a/src/Library/Attacks/AttackData.hpp b/src/Library/Attacks/AttackData.hpp
index 303d451..b6fd44f 100644
--- a/src/Library/Attacks/AttackData.hpp
+++ b/src/Library/Attacks/AttackData.hpp
@@ -1,6 +1,7 @@
 #ifndef CREATURELIB_ATTACKDATA_HPP
 #define CREATURELIB_ATTACKDATA_HPP
 
+#include <Arbutils/ConstString.hpp>
 #include <string>
 #include <unordered_set>
 #include "AttackCategory.hpp"
@@ -17,11 +18,12 @@ namespace CreatureLib::Library {
         uint8_t _baseUsages;
         AttackTarget _target;
         int8_t _priority;
-        std::unordered_set<std::string> _flags;
+        std::unordered_set<Arbutils::CaseInsensitiveConstString> _flags;
 
     public:
         AttackData(std::string name, uint8_t type, AttackCategory category, uint8_t power, uint8_t accuracy,
-                   uint8_t baseUsage, AttackTarget target, int8_t priority, std::unordered_set<std::string> flags);
+                   uint8_t baseUsage, AttackTarget target, int8_t priority,
+                   std::unordered_set<Arbutils::CaseInsensitiveConstString> flags);
         virtual ~AttackData() = default;
 
         inline const std::string& GetName() const { return _name; }
@@ -33,7 +35,7 @@ namespace CreatureLib::Library {
         inline AttackTarget GetTarget() const { return _target; }
         inline int8_t GetPriority() const { return _priority; }
 
-        bool HasFlag(const std::string& key) const;
+        bool HasFlag(const Arbutils::CaseInsensitiveConstString& key) const;
     };
 }
 
diff --git a/src/Library/BaseLibrary.hpp b/src/Library/BaseLibrary.hpp
index 399b591..19ab643 100644
--- a/src/Library/BaseLibrary.hpp
+++ b/src/Library/BaseLibrary.hpp
@@ -1,16 +1,13 @@
 #ifndef CREATURELIB_BASELIBRARY_HPP
 #define CREATURELIB_BASELIBRARY_HPP
 
+#include <Arbutils/ConstString.hpp>
 #include <algorithm>
 #include <string>
 #include <unordered_map>
+
 namespace CreatureLib::Library {
     template <class T> class BaseLibrary {
-        inline static constexpr char charToLower(const char c) { return (c >= 'A' && c <= 'Z') ? c + ('a' - 'A') : c; }
-        inline static uint32_t constexpr Hash(char const* input) {
-            return charToLower(*input) ? static_cast<uint32_t>(charToLower(*input)) + 33 * Hash(input + 1) : 5381;
-        }
-
         std::unordered_map<uint32_t, const T*> _values;
 
     public:
@@ -23,14 +20,13 @@ namespace CreatureLib::Library {
             _values.clear();
         }
 
-        inline void Insert(const char* key, const T* value) { _values.insert({Hash(key), value}); }
-        inline void Insert(const std::string& key, const T* value) { Insert(key.c_str(), value); }
+        inline void Insert(const Arbutils::CaseInsensitiveConstString& key, const T* value) {
+            _values.insert({key.GetHash(), value});
+        }
+        inline void Delete(const Arbutils::CaseInsensitiveConstString& key) { _values.erase(key.GetHash()); }
 
-        inline void Delete(const char* key) { _values.erase(Hash(key)); }
-        inline void Delete(const std::string& key) { Delete(key.c_str()); }
-
-        bool TryGet(const char* name, const T*& out) const {
-            auto find = this->_values.find(Hash(name));
+        bool TryGet(const Arbutils::CaseInsensitiveConstString& name, const T*& out) const {
+            auto find = this->_values.find(name.GetHash());
             if (find == this->_values.end()) {
                 out = nullptr;
                 return false;
@@ -38,16 +34,10 @@ namespace CreatureLib::Library {
             out = find->second;
             return true;
         }
-        bool TryGet(const std::string& name, const T*& out) const {
-            return TryGet(name.c_str(), out);
+        inline const T* Get(const Arbutils::CaseInsensitiveConstString& name) const {
+            return _values.at(name.GetHash());
         }
-
-        inline const T* Get(const char* name) const { return _values.at(Hash(name)); }
-        inline const T* Get(const std::string& name) const { return Get(name.c_str()); }
-
-        inline const T* operator[](const char* name) const { return Get(name); }
-        inline const T* operator[](const std::string& name) const { return Get(name.c_str()); }
-
+        inline const T* operator[](const Arbutils::CaseInsensitiveConstString& name) const { return Get(name); }
         inline const std::unordered_map<uint32_t, const T*>& GetIterator() const { return _values; }
 
         size_t GetCount() const { return _values.size(); }
diff --git a/src/Library/CreatureData/CreatureSpecies.cpp b/src/Library/CreatureData/CreatureSpecies.cpp
index 387b6d9..baf8ccd 100644
--- a/src/Library/CreatureData/CreatureSpecies.cpp
+++ b/src/Library/CreatureData/CreatureSpecies.cpp
@@ -2,21 +2,19 @@
 
 using namespace CreatureLib::Library;
 
-CreatureSpecies::CreatureSpecies(uint16_t id, std::string name, const SpeciesVariant* defaultVariant, float genderRatio,
-                                 std::string growthRate, uint8_t captureRate)
-    : _id(id), _genderRate(genderRatio), _growthRate(std::move(growthRate)), _captureRate(captureRate),
-      _variants({{"default", defaultVariant}}), _name(std::move(name)) {}
+CreatureSpecies::CreatureSpecies(uint16_t id, const Arbutils::CaseInsensitiveConstString& name,
+                                 const SpeciesVariant* defaultVariant, float genderRatio,
+                                 const Arbutils::CaseInsensitiveConstString& growthRate, uint8_t captureRate)
+    : _id(id), _genderRate(genderRatio), _growthRate(growthRate), _captureRate(captureRate),
+      _variants({{"default"_cnc, defaultVariant}}), _name(name) {}
 
-bool CreatureSpecies::HasVariant(const std::string& name) const {
-    auto key = name;
-    std::transform(key.begin(), key.end(), key.begin(), ::tolower);
-    return _variants.find(key) != _variants.end();
+bool CreatureSpecies::HasVariant(const Arbutils::CaseInsensitiveConstString& name) const {
+    return _variants.find(name) != _variants.end();
 }
 
-bool CreatureSpecies::TryGetVariant(const std::string& name, const SpeciesVariant*& out) const {
-    auto key = name;
-    std::transform(key.begin(), key.end(), key.begin(), ::tolower);
-    auto find = _variants.find(key);
+bool CreatureSpecies::TryGetVariant(const Arbutils::CaseInsensitiveConstString& name,
+                                    const SpeciesVariant*& out) const {
+    auto find = _variants.find(name);
     if (find != _variants.end()) {
         out = find->second;
         return true;
@@ -24,20 +22,17 @@ bool CreatureSpecies::TryGetVariant(const std::string& name, const SpeciesVarian
     return false;
 }
 
-const SpeciesVariant* CreatureSpecies::GetVariant(const std::string& name) const {
+const SpeciesVariant* CreatureSpecies::GetVariant(const Arbutils::CaseInsensitiveConstString& name) const {
     auto key = name;
-    std::transform(key.begin(), key.end(), key.begin(), ::tolower);
     return _variants.at(key);
 }
 
-void CreatureSpecies::SetVariant(const std::string& name, const SpeciesVariant* variant) {
-    auto key = name;
-    std::transform(key.begin(), key.end(), key.begin(), ::tolower);
-    auto find = _variants.find(key);
+void CreatureSpecies::SetVariant(const Arbutils::CaseInsensitiveConstString& name, const SpeciesVariant* variant) {
+    auto find = _variants.find(name);
     if (find != _variants.end()) {
         delete find->second;
     }
-    _variants[key] = variant;
+    _variants[name] = variant;
 }
 
 Gender CreatureSpecies::GetRandomGender(Arbutils::Random& rand) const {
@@ -46,6 +41,4 @@ Gender CreatureSpecies::GetRandomGender(Arbutils::Random& rand) const {
     if (val >= this->_genderRate)
         return Gender ::Female;
     return Gender ::Male;
-}
-
-const std::string& CreatureSpecies::GetName() const { return _name; }
+}
\ No newline at end of file
diff --git a/src/Library/CreatureData/CreatureSpecies.hpp b/src/Library/CreatureData/CreatureSpecies.hpp
index d959261..3ae734b 100644
--- a/src/Library/CreatureData/CreatureSpecies.hpp
+++ b/src/Library/CreatureData/CreatureSpecies.hpp
@@ -1,6 +1,7 @@
 #ifndef CREATURELIB_CREATURESPECIES_HPP
 #define CREATURELIB_CREATURESPECIES_HPP
 
+#include <Arbutils/ConstString.hpp>
 #include <string>
 #include <unordered_map>
 #include "../Gender.hpp"
@@ -14,16 +15,17 @@ namespace CreatureLib::Library {
     class CreatureSpecies {
         uint16_t _id;
         float _genderRate;
-        std::string _growthRate;
+        const Arbutils::CaseInsensitiveConstString _growthRate;
         uint8_t _captureRate;
 
     private:
-        std::unordered_map<std::string, const SpeciesVariant*> _variants;
-        std::string _name;
+        std::unordered_map<Arbutils::CaseInsensitiveConstString, const SpeciesVariant*> _variants;
+        Arbutils::CaseInsensitiveConstString _name;
 
     public:
-        CreatureSpecies(uint16_t id, std::string name, const SpeciesVariant* defaultVariant, float genderRatio,
-                        std::string growthRate, uint8_t captureRate);
+        CreatureSpecies(uint16_t id, const Arbutils::CaseInsensitiveConstString& name,
+                        const SpeciesVariant* defaultVariant, float genderRatio,
+                        const Arbutils::CaseInsensitiveConstString& growthRate, uint8_t captureRate);
 
         virtual ~CreatureSpecies() {
             for (auto v : _variants)
@@ -33,18 +35,22 @@ namespace CreatureLib::Library {
 
         inline uint16_t GetId() const { return _id; }
         inline float GetGenderRate() const { return _genderRate; }
-        inline const std::string& GetGrowthRate() const { return _growthRate; }
+        inline const Arbutils::CaseInsensitiveConstString& GetGrowthRate() const { return _growthRate; }
         inline uint8_t GetCaptureRate() const { return _captureRate; }
 
-        [[nodiscard]] bool HasVariant(const std::string& key) const;
-        [[nodiscard]] bool TryGetVariant(const std::string& name, const SpeciesVariant*& out) const;
-        [[nodiscard]] const SpeciesVariant* GetVariant(const std::string& key) const;
+        [[nodiscard]] bool HasVariant(const Arbutils::CaseInsensitiveConstString& key) const;
+        [[nodiscard]] bool TryGetVariant(const Arbutils::CaseInsensitiveConstString& name,
+                                         const SpeciesVariant*& out) const;
+        [[nodiscard]] const SpeciesVariant* GetVariant(const Arbutils::CaseInsensitiveConstString& key) const;
         [[nodiscard]] Gender GetRandomGender(Arbutils::Random& rand) const;
-        [[nodiscard]] const std::string& GetName() const;
+        [[nodiscard]] const Arbutils::CaseInsensitiveConstString& GetName() const { return _name; }
 
-        void SetVariant(const std::string& name, const SpeciesVariant* variant);
+        void SetVariant(const Arbutils::CaseInsensitiveConstString& name, const SpeciesVariant* variant);
 
-        const std::unordered_map<std::string, const SpeciesVariant*>& GetVariantsIterator() const { return _variants; }
+        const std::unordered_map<Arbutils::CaseInsensitiveConstString, const SpeciesVariant*>&
+        GetVariantsIterator() const {
+            return _variants;
+        }
     };
 }
 
diff --git a/src/Library/GrowthRates/GrowthRateLibrary.cpp b/src/Library/GrowthRates/GrowthRateLibrary.cpp
index cb46eb5..6b6e7b0 100644
--- a/src/Library/GrowthRates/GrowthRateLibrary.cpp
+++ b/src/Library/GrowthRates/GrowthRateLibrary.cpp
@@ -2,30 +2,25 @@
 #include <algorithm>
 #include "../../Core/Exceptions/CreatureException.hpp"
 
-uint8_t CreatureLib::Library::GrowthRateLibrary::CalculateLevel(const std::string& growthRate,
+uint8_t CreatureLib::Library::GrowthRateLibrary::CalculateLevel(const Arbutils::CaseInsensitiveConstString& growthRate,
                                                                 uint32_t experience) const {
-    auto g = growthRate;
-    std::transform(g.begin(), g.end(), g.begin(), ::tolower);
-    auto find = _growthRates.find(g);
+    auto find = _growthRates.find(growthRate);
     if (find == _growthRates.end()) {
         throw CreatureException("Invalid growth rate was requested.");
     }
     return find->second->CalculateLevel(experience);
 }
 
-uint32_t CreatureLib::Library::GrowthRateLibrary::CalculateExperience(const std::string& growthRate,
-                                                                      uint8_t level) const {
-    auto g = growthRate;
-    std::transform(g.begin(), g.end(), g.begin(), ::tolower);
-    auto find = _growthRates.find(g);
+uint32_t
+CreatureLib::Library::GrowthRateLibrary::CalculateExperience(const Arbutils::CaseInsensitiveConstString& growthRate,
+                                                             uint8_t level) const {
+    auto find = _growthRates.find(growthRate);
     if (find == _growthRates.end()) {
         throw CreatureException("Invalid growth rate was requested.");
     }
     return find->second->CalculateExperience(level);
 }
-void CreatureLib::Library::GrowthRateLibrary::AddGrowthRate(const std::string& name,
+void CreatureLib::Library::GrowthRateLibrary::AddGrowthRate(const Arbutils::CaseInsensitiveConstString& name,
                                                             CreatureLib::Library::GrowthRate* rate) {
-    auto g = name;
-    std::transform(g.begin(), g.end(), g.begin(), ::tolower);
-    _growthRates.insert({g, rate});
+    _growthRates.insert({name, rate});
 }
diff --git a/src/Library/GrowthRates/GrowthRateLibrary.hpp b/src/Library/GrowthRates/GrowthRateLibrary.hpp
index 21fccf9..5b10bc8 100644
--- a/src/Library/GrowthRates/GrowthRateLibrary.hpp
+++ b/src/Library/GrowthRates/GrowthRateLibrary.hpp
@@ -1,6 +1,7 @@
 #ifndef CREATURELIB_GROWTHRATELIBRARY_HPP
 #define CREATURELIB_GROWTHRATELIBRARY_HPP
 
+#include <Arbutils/ConstString.hpp>
 #include <cstdint>
 #include <string>
 #include <unordered_map>
@@ -9,11 +10,11 @@
 namespace CreatureLib::Library {
     class GrowthRateLibrary {
     private:
-        std::unordered_map<std::string, GrowthRate*> _growthRates;
+        std::unordered_map<Arbutils::CaseInsensitiveConstString, GrowthRate*> _growthRates;
 
     public:
         GrowthRateLibrary(size_t initialCapacity = 10)
-            : _growthRates(std::unordered_map<std::string, GrowthRate*>(initialCapacity)) {}
+            : _growthRates(std::unordered_map<Arbutils::CaseInsensitiveConstString, GrowthRate*>(initialCapacity)) {}
 
         virtual ~GrowthRateLibrary() {
             for (auto gr : _growthRates) {
@@ -21,10 +22,12 @@ namespace CreatureLib::Library {
             }
         }
 
-        [[nodiscard]] uint8_t CalculateLevel(const std::string& growthRate, uint32_t experience) const;
-        [[nodiscard]] uint32_t CalculateExperience(const std::string& growthRate, uint8_t level) const;
+        [[nodiscard]] uint8_t CalculateLevel(const Arbutils::CaseInsensitiveConstString& growthRate,
+                                             uint32_t experience) const;
+        [[nodiscard]] uint32_t CalculateExperience(const Arbutils::CaseInsensitiveConstString& growthRate,
+                                                   uint8_t level) const;
 
-        void AddGrowthRate(const std::string& name, GrowthRate* rate);
+        void AddGrowthRate(const Arbutils::CaseInsensitiveConstString& name, GrowthRate* rate);
     };
 }
 
diff --git a/src/Library/Items/Item.cpp b/src/Library/Items/Item.cpp
index 4af4377..4c4b049 100644
--- a/src/Library/Items/Item.cpp
+++ b/src/Library/Items/Item.cpp
@@ -1,9 +1,9 @@
 #include "Item.hpp"
 
-bool CreatureLib::Library::Item::HasFlag(const std::string& flag) const {
+bool CreatureLib::Library::Item::HasFlag(const Arbutils::CaseInsensitiveConstString& flag) const {
     return this->_flags.find(flag) != this->_flags.end();
 }
 CreatureLib::Library::Item::Item(std::string name, CreatureLib::Library::ItemCategory category,
                                  CreatureLib::Library::BattleItemCategory battleCategory, int32_t price,
-                                 std::unordered_set<std::string> flags)
+                                 std::unordered_set<Arbutils::CaseInsensitiveConstString> flags)
     : _name(name), _category(category), _battleCategory(battleCategory), _price(price), _flags(flags) {}
diff --git a/src/Library/Items/Item.hpp b/src/Library/Items/Item.hpp
index d141126..ffac227 100644
--- a/src/Library/Items/Item.hpp
+++ b/src/Library/Items/Item.hpp
@@ -1,6 +1,7 @@
 #ifndef CREATURELIB_ITEM_HPP
 #define CREATURELIB_ITEM_HPP
 
+#include <Arbutils/ConstString.hpp>
 #include <string>
 #include <unordered_set>
 #include "BattleItemCategory.hpp"
@@ -13,18 +14,18 @@ namespace CreatureLib::Library {
         ItemCategory _category;
         BattleItemCategory _battleCategory;
         int32_t _price;
-        std::unordered_set<std::string> _flags;
+        std::unordered_set<Arbutils::CaseInsensitiveConstString> _flags;
 
     public:
         Item(std::string name, ItemCategory category, BattleItemCategory battleCategory, int32_t price,
-             std::unordered_set<std::string> flags);
+             std::unordered_set<Arbutils::CaseInsensitiveConstString> flags);
 
         inline const std::string& GetName() const { return _name; }
         inline ItemCategory GetCategory() const { return _category; }
         inline BattleItemCategory GetBattleCategory() const { return _battleCategory; }
         inline const int32_t GetPrice() const { return _price; }
 
-        bool HasFlag(const std::string& flag) const;
+        bool HasFlag(const Arbutils::CaseInsensitiveConstString& flag) const;
     };
 }
 
diff --git a/tests/BattleTests/TurnOrderTests.cpp b/tests/BattleTests/TurnOrderTests.cpp
index 1e548cd..53b07cd 100644
--- a/tests/BattleTests/TurnOrderTests.cpp
+++ b/tests/BattleTests/TurnOrderTests.cpp
@@ -28,8 +28,8 @@ TEST_CASE("Turn ordering: Attack before pass", "[Battling]") {
 
 TEST_CASE("Turn ordering: High priority goes before no priority", "[Battling]") {
     auto l = TestLibrary::Get()->GetAttackLibrary();
-    auto a1 = new LearnedAttack(l->Get("standard"), AttackLearnMethod::Unknown);
-    auto a2 = new LearnedAttack(l->Get("highPriority"), AttackLearnMethod::Unknown);
+    auto a1 = new LearnedAttack(l->Get("standard"_cnc), AttackLearnMethod::Unknown);
+    auto a2 = new LearnedAttack(l->Get("highPriority"_cnc), AttackLearnMethod::Unknown);
     auto choice1 = new AttackTurnChoice(nullptr, a1, CreatureIndex(0, 0));
     auto choice2 = new AttackTurnChoice(nullptr, a2, CreatureIndex(0, 0));
     auto vec = std::vector<BaseTurnChoice*>{choice1, choice2};
@@ -50,8 +50,8 @@ TEST_CASE("Turn ordering: High priority goes before no priority", "[Battling]")
 
 TEST_CASE("Turn ordering: Higher priority goes before high priority", "[Battling]") {
     auto l = TestLibrary::Get()->GetAttackLibrary();
-    auto a1 = new LearnedAttack(l->Get("highPriority"), AttackLearnMethod::Unknown);
-    auto a2 = new LearnedAttack(l->Get("higherPriority"), AttackLearnMethod::Unknown);
+    auto a1 = new LearnedAttack(l->Get("highPriority"_cnc), AttackLearnMethod::Unknown);
+    auto a2 = new LearnedAttack(l->Get("higherPriority"_cnc), AttackLearnMethod::Unknown);
     auto choice1 = new AttackTurnChoice(nullptr, a1, CreatureIndex(0, 0));
     auto choice2 = new AttackTurnChoice(nullptr, a2, CreatureIndex(0, 0));
     auto vec = std::vector<BaseTurnChoice*>{choice1, choice2};
@@ -72,8 +72,8 @@ TEST_CASE("Turn ordering: Higher priority goes before high priority", "[Battling
 
 TEST_CASE("Turn ordering: High priority goes before low priority", "[Battling]") {
     auto l = TestLibrary::Get()->GetAttackLibrary();
-    auto a1 = new LearnedAttack(l->Get("lowPriority"), AttackLearnMethod::Unknown);
-    auto a2 = new LearnedAttack(l->Get("higherPriority"), AttackLearnMethod::Unknown);
+    auto a1 = new LearnedAttack(l->Get("lowPriority"_cnc), AttackLearnMethod::Unknown);
+    auto a2 = new LearnedAttack(l->Get("higherPriority"_cnc), AttackLearnMethod::Unknown);
     auto choice1 = new AttackTurnChoice(nullptr, a1, CreatureIndex(0, 0));
     auto choice2 = new AttackTurnChoice(nullptr, a2, CreatureIndex(0, 0));
     auto vec = std::vector<BaseTurnChoice*>{choice1, choice2};
@@ -94,8 +94,8 @@ TEST_CASE("Turn ordering: High priority goes before low priority", "[Battling]")
 
 TEST_CASE("Turn ordering: No priority goes before low priority", "[Battling]") {
     auto l = TestLibrary::Get()->GetAttackLibrary();
-    auto a1 = new LearnedAttack(l->Get("lowPriority"), AttackLearnMethod::Unknown);
-    auto a2 = new LearnedAttack(l->Get("standard"), AttackLearnMethod::Unknown);
+    auto a1 = new LearnedAttack(l->Get("lowPriority"_cnc), AttackLearnMethod::Unknown);
+    auto a2 = new LearnedAttack(l->Get("standard"_cnc), AttackLearnMethod::Unknown);
     auto choice1 = new AttackTurnChoice(nullptr, a1, CreatureIndex(0, 0));
     auto choice2 = new AttackTurnChoice(nullptr, a2, CreatureIndex(0, 0));
     auto vec = std::vector<BaseTurnChoice*>{choice1, choice2};
diff --git a/tests/Integration/BattleIntegrations.cpp b/tests/Integration/BattleIntegrations.cpp
index 4c62864..906495e 100644
--- a/tests/Integration/BattleIntegrations.cpp
+++ b/tests/Integration/BattleIntegrations.cpp
@@ -13,7 +13,8 @@ using namespace Battling;
 
 TEST_CASE("Create Party", "[Integrations]") {
     auto library = TestLibrary::Get();
-    auto c1 = CreateCreature(library, "testSpecies1", 50).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c1 =
+        CreateCreature(library, "testSpecies1", 50).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party1{c1};
     auto battleParty = BattleParty(&party1, {CreatureIndex(0, 0)});
     REQUIRE(battleParty.GetParty()->GetAtIndex(0) == c1);
@@ -21,10 +22,12 @@ TEST_CASE("Create Party", "[Integrations]") {
 
 TEST_CASE("Create Battle", "[Integrations]") {
     auto library = TestLibrary::Get();
-    auto c1 = CreateCreature(library, "testSpecies1", 50).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c1 =
+        CreateCreature(library, "testSpecies1", 50).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party1{c1};
     auto battleParty1 = BattleParty(&party1, {CreatureIndex(0, 0)});
-    auto c2 = CreateCreature(library, "testSpecies1", 50).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c2 =
+        CreateCreature(library, "testSpecies1", 50).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party2{c2};
     auto battleParty2 = BattleParty(&party2, {CreatureIndex(1, 0)});
 
@@ -33,10 +36,12 @@ TEST_CASE("Create Battle", "[Integrations]") {
 
 TEST_CASE("Use damaging move", "[Integrations]") {
     auto library = TestLibrary::Get();
-    auto c1 = CreateCreature(library, "testSpecies1", 50).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c1 =
+        CreateCreature(library, "testSpecies1", 50).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party1{c1};
     auto battleParty1 = BattleParty(&party1, {CreatureIndex(0, 0)});
-    auto c2 = CreateCreature(library, "testSpecies1", 50).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c2 =
+        CreateCreature(library, "testSpecies1", 50).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party2{c2};
     auto battleParty2 = BattleParty(&party2, {CreatureIndex(1, 0)});
 
@@ -53,10 +58,12 @@ TEST_CASE("Use damaging move", "[Integrations]") {
 
 TEST_CASE("Finish battle when all battle of one side have fainted", "[Integrations]") {
     auto library = TestLibrary::Get();
-    auto c1 = CreateCreature(library, "testSpecies1", 50).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c1 =
+        CreateCreature(library, "testSpecies1", 50).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party1{c1};
     auto battleParty1 = BattleParty(&party1, {CreatureIndex(0, 0)});
-    auto c2 = CreateCreature(library, "testSpecies1", 50).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c2 =
+        CreateCreature(library, "testSpecies1", 50).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party2{c2};
     auto battleParty2 = BattleParty(&party2, {CreatureIndex(1, 0)});
 
@@ -86,10 +93,12 @@ TEST_CASE("Finish battle when all battle of one side have fainted", "[Integratio
 
 TEST_CASE("When creature is dealt enough damage, faint it and mark battle as ended", "[Integrations]") {
     auto library = TestLibrary::Get();
-    auto c1 = CreateCreature(library, "testSpecies1", 100).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c1 =
+        CreateCreature(library, "testSpecies1", 100).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party1{c1};
     auto battleParty1 = BattleParty(&party1, {CreatureIndex(0, 0)});
-    auto c2 = CreateCreature(library, "testSpecies1", 1).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c2 =
+        CreateCreature(library, "testSpecies1", 1).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party2{c2};
     auto battleParty2 = BattleParty(&party2, {CreatureIndex(1, 0)});
 
@@ -113,11 +122,14 @@ TEST_CASE("When creature is dealt enough damage, faint it and mark battle as end
 
 TEST_CASE("When another creature is available on faint, make sure the battle hasn't ended", "[Integrations]") {
     auto library = TestLibrary::Get();
-    auto c1 = CreateCreature(library, "testSpecies1", 100).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c1 =
+        CreateCreature(library, "testSpecies1", 100).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party1{c1};
     auto battleParty1 = BattleParty(&party1, {CreatureIndex(0, 0)});
-    auto c2 = CreateCreature(library, "testSpecies1", 1).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
-    auto c3 = CreateCreature(library, "testSpecies1", 1).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c2 =
+        CreateCreature(library, "testSpecies1", 1).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
+    auto c3 =
+        CreateCreature(library, "testSpecies1", 1).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party2{c2, c3};
     auto battleParty2 = BattleParty(&party2, {CreatureIndex(1, 0)});
 
@@ -148,11 +160,14 @@ TEST_CASE("When another creature is available on faint, make sure the battle has
 
 TEST_CASE("Switch Creature in", "[Integrations]") {
     auto library = TestLibrary::Get();
-    auto c1 = CreateCreature(library, "testSpecies1", 100).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
-    auto c2 = CreateCreature(library, "testSpecies1", 1).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c1 =
+        CreateCreature(library, "testSpecies1", 100).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
+    auto c2 =
+        CreateCreature(library, "testSpecies1", 1).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party1{c1, c2};
     auto battleParty1 = BattleParty(&party1, {CreatureIndex(0, 0)});
-    auto c3 = CreateCreature(library, "testSpecies1", 1).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c3 =
+        CreateCreature(library, "testSpecies1", 1).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party2{c3};
     auto battleParty2 = BattleParty(&party2, {CreatureIndex(1, 0)});
 
@@ -171,11 +186,14 @@ TEST_CASE("Switch Creature in", "[Integrations]") {
 
 TEST_CASE("Switch Creature in, but have attack aimed at it. Attack should hit new creature", "[Integrations]") {
     auto library = TestLibrary::Get();
-    auto c1 = CreateCreature(library, "testSpecies1", 50).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
-    auto c2 = CreateCreature(library, "testSpecies1", 50).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c1 =
+        CreateCreature(library, "testSpecies1", 50).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
+    auto c2 =
+        CreateCreature(library, "testSpecies1", 50).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party1{c1, c2};
     auto battleParty1 = BattleParty(&party1, {CreatureIndex(0, 0)});
-    auto c3 = CreateCreature(library, "testSpecies1", 50).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c3 =
+        CreateCreature(library, "testSpecies1", 50).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party2{c3};
     auto battleParty2 = BattleParty(&party2, {CreatureIndex(1, 0)});
 
@@ -193,11 +211,14 @@ TEST_CASE("Switch Creature in, but have attack aimed at it. Attack should hit ne
 
 TEST_CASE("Switch Creature in, mark as seen opponent for opponent", "[Integrations]") {
     auto library = TestLibrary::Get();
-    auto c1 = CreateCreature(library, "testSpecies1", 100).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
-    auto c2 = CreateCreature(library, "testSpecies1", 1).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c1 =
+        CreateCreature(library, "testSpecies1", 100).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
+    auto c2 =
+        CreateCreature(library, "testSpecies1", 1).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party1{c1, c2};
     auto battleParty1 = BattleParty(&party1, {CreatureIndex(0, 0)});
-    auto c3 = CreateCreature(library, "testSpecies1", 1).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c3 =
+        CreateCreature(library, "testSpecies1", 1).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party2{c3};
     auto battleParty2 = BattleParty(&party2, {CreatureIndex(1, 0)});
 
@@ -229,10 +250,12 @@ TEST_CASE("Switch Creature in, mark as seen opponent for opponent", "[Integratio
 
 TEST_CASE("Flee Battle", "[Integrations]") {
     auto library = TestLibrary::Get();
-    auto c1 = CreateCreature(library, "testSpecies1", 100).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c1 =
+        CreateCreature(library, "testSpecies1", 100).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party1{c1};
     auto battleParty1 = BattleParty(&party1, {CreatureIndex(0, 0)});
-    auto c2 = CreateCreature(library, "testSpecies1", 1).WithAttack("standard", AttackLearnMethod::Unknown)->Create();
+    auto c2 =
+        CreateCreature(library, "testSpecies1", 1).WithAttack("standard"_cnc, AttackLearnMethod::Unknown)->Create();
     CreatureParty party2{c2};
     auto battleParty2 = BattleParty(&party2, {CreatureIndex(1, 0)});
 
diff --git a/tests/LibraryTests/CreatureTests.cpp b/tests/LibraryTests/CreatureTests.cpp
index 1166647..dc4cf18 100644
--- a/tests/LibraryTests/CreatureTests.cpp
+++ b/tests/LibraryTests/CreatureTests.cpp
@@ -13,7 +13,7 @@ TEST_CASE("Create basic creature", "[Library]") {
 TEST_CASE("Get creature species", "[Library]") {
     auto library = TestLibrary::Get();
     auto creature = CreateCreature(library, "testSpecies1", 1).Create();
-    REQUIRE(creature->GetSpecies()->GetName() == "testSpecies1");
+    REQUIRE(creature->GetSpecies()->GetName() == "testSpecies1"_cnc);
     delete creature;
 }
 
diff --git a/tests/TestLibrary/TestLibrary.cpp b/tests/TestLibrary/TestLibrary.cpp
index c21c881..f8a2889 100644
--- a/tests/TestLibrary/TestLibrary.cpp
+++ b/tests/TestLibrary/TestLibrary.cpp
@@ -22,25 +22,25 @@ BattleLibrary* TestLibrary::Get() {
 
 SpeciesLibrary* TestLibrary::BuildSpeciesLibrary() {
     auto l = new SpeciesLibrary();
-    l->Insert("testSpecies1",
-              new CreatureSpecies(0, "testSpecies1",
+    l->Insert("testSpecies1"_cnc,
+              new CreatureSpecies(0, "testSpecies1"_cnc,
                                   new SpeciesVariant("default", 1, 1, 10, {0, 1},
                                                      StatisticSet<uint16_t>(10, 10, 10, 10, 10, 10), {"testTalent"},
                                                      {"testSecretTalent"}, new LearnableAttacks(100)),
-                                  0.5f, "testGrowthRate", 5));
+                                  0.5f, "testGrowthRate"_cnc, 5));
     return l;
 }
 
 AttackLibrary* TestLibrary::BuildAttackLibrary() {
     auto l = new AttackLibrary();
-    l->Insert("standard", new AttackData("standard", 0, AttackCategory::Physical, 20, 100, 30,
-                                         AttackTarget::AdjacentOpponent, 0, {}));
-    l->Insert("highPriority", new AttackData("highPriority", 0, AttackCategory::Physical, 20, 100, 30,
-                                             AttackTarget::AdjacentOpponent, 1, {}));
-    l->Insert("higherPriority", new AttackData("higherPriority", 0, AttackCategory::Physical, 20, 100, 30,
-                                               AttackTarget::AdjacentOpponent, 2, {}));
-    l->Insert("lowPriority", new AttackData("lowPriority", 0, AttackCategory::Physical, 20, 100, 30,
-                                            AttackTarget::AdjacentOpponent, -1, {}));
+    l->Insert("standard"_cnc, new AttackData("standard", 0, AttackCategory::Physical, 20, 100, 30,
+                                             AttackTarget::AdjacentOpponent, 0, {}));
+    l->Insert("highPriority"_cnc, new AttackData("highPriority", 0, AttackCategory::Physical, 20, 100, 30,
+                                                 AttackTarget::AdjacentOpponent, 1, {}));
+    l->Insert("higherPriority"_cnc, new AttackData("higherPriority", 0, AttackCategory::Physical, 20, 100, 30,
+                                                   AttackTarget::AdjacentOpponent, 2, {}));
+    l->Insert("lowPriority"_cnc, new AttackData("lowPriority", 0, AttackCategory::Physical, 20, 100, 30,
+                                                AttackTarget::AdjacentOpponent, -1, {}));
     return l;
 }
 
@@ -51,7 +51,7 @@ ItemLibrary* TestLibrary::BuildItemLibrary() {
 
 GrowthRateLibrary* TestLibrary::BuildGrowthRateLibrary() {
     auto l = new GrowthRateLibrary();
-    l->AddGrowthRate("testGrowthRate", new LookupGrowthRate());
+    l->AddGrowthRate("testGrowthRate"_cnc, new LookupGrowthRate());
     return l;
 }