Elder Brain

When Elder Brain enters the Battlefield, exile all
non-blue or non-black creatures. When Elder
Brain is placed into any graveyard from play,
return all exiled creatures to their owner's hand.
{1}{u/b}, Sacrifice a Creature: Place target exiled
creature onto the battlefield under your control.
At the end of the turn, return it to it's owner's
hand. While on the Battlefield, it is a Black
Drone in addition to it's other colors and types.