Sauron, Lord of the Rings

Rule them All - When Sauron, Lord of the Rings enters the battlefield, create The One Ring, a legendary artifact equipment and attach it to a creature of your choice an opponent controls. It has "At the beginning of the next end step, gain control of the equipped creature. You may equip The One Ring to creatures your opponents control. Equip {3}."
At the beginning of your upkeep, if you control nine or more creatures you don't own, you win