Armageddon (EFA - A)

You open a portal to the outer planes and summon celestials to battle the forces of evil. The celestials heed your summons only if you are a being of pure, unstained good and there are creatures of inarguable evil present to destroy. When the celestials arrive, they obey you explicitly and never attack you, even if another creature gains control over them.

On the turn during which you cast the spell, 2 Deva  arrive. On each turn thereafter for 3 turns, 2 more Devas arrive. On the 5th turn, a solar arrives. At the end of the spell, or when the fight is over, the celestials disappear, returning to their home plane.