Jaws of Defeat, Tree of Perdition, and Mass Hysteria

Prerequisites

• Jaws of Defeat on the battlefield
• Tree of Perdition in hand
• Mass Hysteria on the battlefield
• available

Steps

1. Cast Tree of Perdition by paying
2. When Tree of Perdition enters the battlefield, Jaws of Defeat triggers, targeting an opponent
3. If the opponent has 13 or more life, hold priority and then activate Tree of Perdition by tapping it, swapping its toughness with an opponent's life total
4. Resolve the Jaws of Defeat trigger, causing the opponent targeted in step 3 to lose life equal to Tree of Perdition's toughness
5. The opponent loses the game as a state-based action due to having 0 or less life

Results

• Target opponent loses the game
• Infinite lifeloss for target opponent