ok so this should be the way to go

resource_definitions/RDamageModifier.cs

@@ -6,6 +6,8 @@ using Movementtests.systems.damage;
 [GlobalClass]
 public partial class RDamageModifier : Resource, IDamageable
 {
+    public event Action<IDamageable, float> DamageTaken;
+    
     [Export]
     public EDamageTypes DamageType = EDamageTypes.Normal;
     [Export]
@@ -26,6 +28,7 @@ public partial class RDamageModifier : Resource, IDamageable
     {
         if (damage.DamageType != DamageType) return 0;
         var finalDamage = damage.DamageDealt * Modifier;
+        DamageTaken?.Invoke(this, finalDamage);
         return finalDamage;
     }
 }