Mortuary + Ashnod's Altar + Bolas's Citadel + Bontu's Monument

Mortuary

Ashnod's Altar

Bolas's Citadel

Bontu's Monument

How it works

1. Activate Ashnod's Altar by sacrificing a creature with mana value 1 or less.
2. When the creature dies, Mortuary triggers, putting the creature from your graveyard onto the top of your library.
3. Cast the creature from the top of your library by paying 1 life.
4. Bontu's Monument triggers, causing you to gain 1 life and each opponent to lose 1 life.
5. Repeat.

This elegant loop turns a humble 1-mana creature into an endless engine of life and mana. By leveraging Bolas's Citadel, you bypass traditional mana costs to cast that creature straight from the top of your library for a mere 1 life, a cost immediately offset by the life gained from Bontu's Monument whenever you cast a creature spell. When you sacrifice that creature to Ashnod's Altar, you generate a surplus of colorless mana while Mortuary steps in to instantly recycle the creature back to the top of your library. Bontu's Monument also chips away at your opponents with every iteration, while the monument's cost reduction helps ease the burden, creating a self-sustaining cycle of sacrifice, rebirth, and drain.