Liberator, Urza's Battlethopter (Promo Pack) [The Brothers' War Promos]

Flash

Flying

You may cast colorless spells and artifact spells as though they had flash.

Whenever you cast a spell, if the amount of mana spent to cast that spell is greater than Liberator, Urza's Battlethopter's power, put a +1/+1 counter on Liberator.