Golgari Thug + Viscera Seer + Healer of the Pride + Bolas's Citadel

Golgari Thug

Viscera Seer

Healer of the Pride

Bolas's Citadel

How it works

1. Activate Viscera Seer by sacrificing Golgari Thug.
2. When Golgari Thug dies, it triggers, putting it from your graveyard onto the top of your library.
3. Resolve the Viscera Seer ability.
4. Cast Golgari Thug from the top of your library by paying 2 life.
5. When Golgari Thug enters, Healer of the Pride triggers, causing you to gain 2 life.
6. Repeat.

This loop turns Bolas's Citadel into a self-sustaining engine by letting you cast creatures straight from the top of your library for a mere 2 life instead of paying mana. Viscera Seer provides the sacrifice outlet to clear the way, while Golgari Thug keeps returning itself to the top of your library via its own death trigger to be cast over and over again. Every iteration of this cycle is cushioned by Healer of the Pride, which neatly cancels out the life lost to Bolas's Citadel with a steady stream of life gain.