Mortuary + Bontu's Monument + Phantom Train + Gwenom, Remorseless

Mortuary

Bontu's Monument

Phantom Train

Gwenom, Remorseless

How it works

1. Activate Phantom Train by sacrificing a creature with mana value 1 or less.
2. When the creature dies, Mortuary triggers, putting the creature from your graveyard onto the top of your library.
3. Resolve the Phantom Train ability.
4. Cast the creature from the top of your library by paying 1 life.
5. Bontu's Monument triggers, causing you to gain 1 life and each opponent to lose 1 life.
6. Repeat.

This loop achieves immortality and infinite drain by turning your graveyard into a revolving door for cheap creatures, all fueled by Gwenom, Remorseless allowing you to cast cards directly off the top of your library for life instead of mana. When you feed a creature to Phantom Train, Mortuary instantly catches it on its way to the graveyard and places it right back on top of your library, primed to be re-cast. Bontu's Monument makes those creature spells even easier to cast while turning each repetition into a life-drain engine against your opponents, letting you safely pay the life costs required by Gwenom, Remorseless.