Adds more abilities

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

@@ -0,0 +1,20 @@
+namespace PkmnLib.Plugin.Gen7.Scripts.Abilities;
+
+/// <summary>
+/// Contrary is an ability that inverts all stat changes for the Pokémon.
+/// When a stat would normally be raised, it is lowered instead, and vice versa.
+/// This applies to both self-inflicted stat changes and those caused by other Pokémon.
+/// 
+/// <see href="https://bulbapedia.bulbagarden.net/wiki/Contrary_(Ability)">Bulbapedia - Contrary</see>
+/// </summary>
+[Script(ScriptCategory.Ability, "contrary")]
+public class Contrary : Script
+{
+    /// <inheritdoc />
+    public override void ChangeStatBoostChange(IPokemon target, Statistic stat, bool selfInflicted, ref sbyte amount)
+    {
+        // Invert the stat change
+        amount = (sbyte)-amount;
+        target.BattleData?.Battle.EventHook.Invoke(new AbilityTriggerEvent(target));
+    }
+}