The Void

Trample, Indestructible
The Void can't be sacrificed.
At the beginning of your upkeep, if you control The Void, contain it or you lose the game.
(To contain it, you must sacrifice two nonland permanents and discard two cards).

Whenever The Void deals combat damage to a player, that player gains control of it at the end of turn.

If the Void would change zones, instead it remains on the battlefield under the control of the active player.