Mairsil, the Pretender + Hateflayer + Tree of Perdition

Mairsil, the Pretender

Hateflayer

Tree of Perdition

How it works

1. Activate Mairsil using Tree of Perdition's ability by tapping it, exchanging target opponent's life total with Mairsil's toughness.
2. Activate Mairsil using Hateflayer's ability by paying 2 and untapping it, dealing damage equal to Mairsil's power to the opponent.
3. The opponent loses the game due to having zero or less life.