Sea Crypt
Land (Rare)

Sea Crypt enters the battlefield tapped unless you sacrifice an artifact creature.

Tap: Add 1 to your mana pool.

Tap: Add U or B to your mana pool. Each opponent gains 1 life.

1U: Sea Crypt becomes a 1/1 blue and black Wizard creature with flying until end of turn. It's still a land.

Allan Prescott