Mortuary + Ravenous Baloth + Bolas's Citadel

Mortuary

Ravenous Baloth

Bolas's Citadel

How it works

1. Activate Ravenous Baloth by sacrificing itself.
2. When Ravenous Baloth dies, Mortuary triggers, putting Ravenous Baloth on top of your library from your graveyard.
3. Resolve the Ravenous Baloth ability, causing you to gain 4 life.
4. Cast Ravenous Baloth from the top of your library by paying 4 life.
5. Repeat.

This cunning loop transforms the top of your library into an endless recursion engine, fueled entirely by life rather than mana. With Bolas's Citadel allowing you to cast creatures straight from the top of your deck, you simply deploy Ravenous Baloth, sacrifice it to its own ability to gain 4 life, and let Mortuary quietly intercept it on the way to the graveyard to place it right back on top of your library. Because casting the Beast from the top costs you 4 life via Bolas's Citadel and sacrificing it gains you 4 life right back, your life total remains completely neutral while generating an endless storm of creature deaths, enters-the-battlefield triggers, and sacrifices.