The Doubling Curse

Enchant Creature
Double everything on enchanted creature but the
power and toughness then enchanted creature gains double strike
Fortnite 6/7 (You may wait 2 turns after this enchantment is put on the battlefield and
after the 2 turns are up pay {6}, if you do remove
this enchantment from the creature and it becomes
a 3/7 horror nightmare creature with double strike)