Mortuary + Vindictive Vampire + Blood Pet + Gwenom, Remorseless

Mortuary

Vindictive Vampire

Blood Pet

Gwenom, Remorseless

How it works

1. Activate Blood Pet by sacrificing it.
2. When Blood Pet dies, Mortuary and Vindictive Vampire trigger.
3. Resolve the Mortuary trigger, putting Blood Pet from your graveyard onto the top of your library.
4. Resolve the Vindictive Vampire trigger, dealing 1 damage to each opponent and causing you to gain 1 life.
5. Resolve the Blood Pet ability.
6. Cast Blood Pet from the top of your library by paying 1 life.
7. Repeat.

This infinite loop uses Mortuary as a clever sorting engine that intercepts your dying creatures and immediately puts them back on top of your library instead of letting them stay in the graveyard. Once Blood Pet is sacrificed for black mana, its death triggers Vindictive Vampire to drain your opponents and heal you, while Mortuary sends the sacrifice back to your library. Because Gwenom, Remorseless grants you the ability to cast spells directly from the top of your library and pay life instead of mana, you can immediately replay the same Blood Pet for a mere 1 life. This creates a self-sustaining cycle that generates infinite black mana, infinite death triggers, and infinite damage to close out the game.