Suzumiya's Curse

When Suzumiya's Curse enters the battlefield,
target opponent gains control of it.
When you gain control of Suzumiya's Curse,
exile all creatures you control. For each creature
exiled this way, the owner of Suzumiya's Curse
creates a 6/6 Black Demon Spirit token with
flying, trample, and haste.
"Oops!... I'm sorry!... I didn't realize I was making a deal with a demon..."