Mortuary + Bile Urchin + Bolas's Citadel + Proper Burial

Mortuary

Bile Urchin

Bolas's Citadel

Proper Burial

How it works

1. Activate Bile Urchin by sacrificing it.
2. When Bile Urchin dies, Mortuary and Proper Burial trigger.
3. Resolve the Mortuary trigger, putting Bile Urchin from your graveyard onto the top of your library.
4. Resolve the Proper Burial trigger, causing you to gain 1 life
5. Resolve the Bile Urchin ability.
6. Cast Bile Urchin from the top of your library by paying 1 life.
7. Repeat.

This loop turns Bile Urchin into an endlessly recurring weapon by leaning entirely on Bolas's Citadel to cast it straight from the top of your library for a mere 1 life instead of its usual mana cost. Every time you sacrifice the Urchin, Mortuary instantly recycles it back to the top of your library so the Citadel can play it again. Meanwhile, Proper Burial steps in to recover the life you spent casting the Urchin, neutralizing the life payment and leaving you free to drain your opponents indefinitely.