Triskaidekaphobia, and Tree of Perdition

Prerequisites

• Triskaidekaphobia on the battlefield
• Tree of Perdition on the battlefield

Steps

1. At the beginning of your upkeep, Triskaidekaphobia triggers; hold priority
2. Activate Tree of Perdition to make target opponent's life total 13
3. Allow Triskaidekaphobia's trigger to resolve, making that opponent lose the game

Results

• Target player loses the game