Liberator, Urza's Battlethopter [The Brothers' War Prerelease Promos] Rat Warlock Whenever an Army you control

Whenever an Army you control deals combat damage to a player

then return it to the battlefield under its owner's control

you may search your library for an instant or sorcery card with mana value 2 or less

Primal Storm attacks

Liberator, Urza's Battlethopter [The Brothers' War Prerelease Promos] Rat Warlock Whenever an Army you controlSet: The Brothers' War Prerelease Promos Type: Legendary Artifact Creature Thopter Rarity: Rare Cost: {3} 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.