Arlavek, Arcane Fury

Flash
Defender, Flying
Whenever you cast an instant or sorcery spell, if Arlavek has less than 4 charge counters on it, it deals X damage to itself and target opponent, where X is that spell's converted mana cost.
Then, put a charge counter on Arlavek, Arcane Fury.
As long as Arlavek has 4 or more charge counters on it, it can attack as though it didn't have defender.