Phage the Untouchable + Hive Mind + Theoretical Duplication
Phage the Untouchable
Hive Mind
Theoretical Duplication
Each opponent loses the game
How it works
Cast Theoretical Duplication by paying 2.
Hive Mind triggers, causing all opponent to copy Theoretical Duplication.
Resolve each Theoretical Duplication, causing all players to create a token of all creatures that enter the battlefield under an opponent's control this turn.
Cast Phage by paying 3.
Each opponent's Theoretical Duplication triggers.
Resolve the first Theoretical Duplication trigger, causing the opponent to create a token copy of Phage.
The Phage token enters the battlefield, causing its controller to lose the game.