Mortuary + Cruel Celebrant + Bolas's Citadel + Blood Pet

Mortuary

Cruel Celebrant

Bolas's Citadel

Blood Pet

How it works

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

This clever loop lets you drain the table dry by continuously sacrificing and recasting a single tiny creature. It is anchored by Bolas's Citadel, which turns the top of your library into your hand and swaps mana costs for life payments. Since Blood Pet costs only one mana, the Citadel lets you recast it directly from the top for just a single point of life. When you sacrifice Blood Pet to add a black mana, Mortuary swoops in to intercept it on the way to the graveyard, instantly stacking the Pet right back onto the top of your library. Meanwhile, Cruel Celebrant watches the sacrifice happen and drains your opponents while offsetting the life you spent to cast the spell through Bolas's Citadel. The result is a self-sustaining cycle that generates infinite black mana, infinite deaths, and infinite life drain to close out the game.