800General
Example: Alex casts Mind Control, an Aura that reads, “You control enchanted creature,” on Bianca’s Assault Griffin. If Alex leaves the game, so does Mind Control, and Assault Griffin reverts to Bianca’s control. If, instead, Bianca leaves the game, so does Assault Griffin, and Mind Control is put into Alex’s graveyard.
Example: Alex casts Act of Treason, which reads, in part, “Gain control of target creature until end of turn,” targeting Bianca’s Runeclaw Bears. If Alex leaves the game, Act of Treason’s change-of-control effect ends and Runeclaw Bears reverts to Bianca’s control.
Example: Alex casts Bribery, which reads, “Search target opponent’s library for a creature card and put that card onto the battlefield under your control. Then that player shuffles their library,” targeting Bianca. Alex puts Serra Angel onto the battlefield from Bianca’s library. If Bianca leaves the game, Serra Angel also leaves the game. If, instead, Alex leaves the game, Serra Angel is exiled.
Example: Alex controls Genesis Chamber, which reads, “Whenever a nontoken creature enters, if Genesis Chamber is untapped, that creature’s controller creates a 1/1 colorless Myr artifact creature token.” If Alex leaves the game, all such Myr tokens that entered the battlefield under Alex’s control leave the game, and all such Myr tokens that entered the battlefield under any other player’s control remain in the game.
Example: Astral Slide is an enchantment that reads, “Whenever a player cycles a card, you may exile target creature. If you do, return that creature to the battlefield under its owner’s control at the beginning of the next end step.” During Alex’s turn, Bianca uses Astral Slide’s ability to exile Alex’s Hypnotic Specter. Before the end of that turn, Bianca leaves the game. At the beginning of the end step, the delayed triggered ability generated by Astral Slide that would return Hypnotic Specter to the battlefield triggers, but it isn’t put on the stack. Hypnotic Specter never returns to the battlefield.