Coat in Shadows

Exile target creature you both own and control and put a decoy counter on it, if you do put a 2/2 colorless decoy creature token onto the battlefield it has "when this creature leaves the battlefield you may put a card you own with a decoy counter on it from exile onto the battlefield under your control".
At the begining of your next upkeep pay {4} if you don't remove the decoy counter from the creature in exile.