More abilities, refactor custom triggers to be typed.

Plugins/PkmnLib.Plugin.Gen7/Scripts/Abilities/MagicGuard.cs

@@ -0,0 +1,25 @@
+namespace PkmnLib.Plugin.Gen7.Scripts.Abilities;
+
+/// <summary>
+/// Magic Guard is an ability that prevents all damage except from direct attacks.
+///
+/// <see href="https://bulbapedia.bulbagarden.net/wiki/Magic_Guard_(Ability)">Bulbapedia - Magic Guard</see>
+/// </summary>
+[Script(ScriptCategory.Ability, "magic_guard")]
+public class MagicGuard : Script
+{
+    /// <inheritdoc />
+    public override void ChangeIncomingDamage(IPokemon pokemon, DamageSource source, ref uint damage)
+    {
+        // Magic Guard doesn't work if the Pokémon is not in battle.
+        if (pokemon.BattleData is null)
+            return;
+
+        if (source is DamageSource.MoveDamage or DamageSource.Struggle or DamageSource.FormChange)
+        {
+            // If the damage is from a move, struggle, or form change, we don't prevent it.
+            return;
+        }
+        damage = 0;
+    }
+}