Mortuary + Fleshtaker + Bile Urchin + Gwenom, Remorseless

Mortuary

Fleshtaker

Bile Urchin

Gwenom, Remorseless

How it works

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