Mortuary + Carmen, Cruel Skymarcher + Bolas's Citadel + Carrion Feeder

Mortuary

Carmen, Cruel Skymarcher

Bolas's Citadel

Carrion Feeder

How it works

1. Activate Carrion Feeder by sacrificing it.
2. When Carrion Feeder dies, Mortuary and Carmen trigger.
3. Resolve the Mortuary trigger, putting Carrion Feeder from your graveyard onto the top of your library.
4. Resolve the Carmen trigger, causing you to gain 1 life and put a +1/+1 counter on Carmen.
5. Resolve the Carrion Feeder ability.
6. Cast Carrion Feeder from the top of your library by paying 1 life.
7. Repeat.

This recursive loop uses Mortuary to instantly reroute any creature sent to the graveyard straight back to the top of your library. Bolas's Citadel then bypasses traditional mana costs, letting you recast that creature from the library for a mere drop of life while keeping your hand free. Meanwhile, Carmen, Cruel Skymarcher grows larger and grants lifegain with every sacrifice, buffering the life you spend on Bolas's Citadel. Finally, Carrion Feeder acts as the designated sacrifice outlet that fuels the entire engine over and over again.