Tree of Perdition, Dollhouse of Horrors, and Corpse Knight

Prerequisites

• Tree of Perdition in the graveyard
• Dollhouse of Horrors on the battlefield
• Corpse Knight on the battlefield
• You do not control a Construct
• available

Steps

1. Activate Dollhouse of Horrors by paying , tapping it and exiling Tree of Perdition from your graveyard, creating a token copy of Tree of Perdition that is a 0/0 Construct with haste
2. When the Tree of Perdition token enters the battlefield, Corpse Knight triggers
3. Holding priority, activate the Tree of Perdition token by tapping it, swapping an opponent's life total with Tree of Perdition's toughness
4. Resolve the Corpse Knight trigger, causing each opponent to lose 1 life
5. The opponent whose life total was swapped loses the game due to having zero or les life

Results

• Near-infinite lifeloss for target opponent
• Target opponent loses the game