public abstract class TargetingStrategy {
    protected Ability ability;
    protected TargetingManager targetingManager;
    protected bool isTargeting = false;
    
    public bool IsTargeting => isTargeting;
    
    public abstract void Start(Ability ability, TargetingManager targetingManager);
    public virtual void Update() { }
    public virtual void Cancel() { }
}

public class SelfTargeting : TargetingStrategy {
    public override void Start(Ability ability, TargetingManager targetingManager) {
        if (targetingManager.transform.TryGetComponent<IDamageable>(out var target)) {
            ability.Execute(target);
        }
    }
}