Survey Mechan + Mortuary + Ashnod's Altar + Tormod, the Desecrator + Primal Vigor

Survey Mechan

Mortuary

Ashnod's Altar

Tormod, the Desecrator

Primal Vigor

How it works

1. Activate Survey Mechan by sacrificing it.
2. When Survey Mechan dies, Mortuary triggers, putting Survey Mechan from your graveyard onto the top of your library.
3. Tormod triggers, creating two creature tokens.
4. Resolve the Survey Mechan ability, dealing 3 damage to any target and causing you to draw three cards and gain 3 life.
5. Activate Ashnod's Altar twice by sacrificing the two creature tokens, adding CCCC.
6. Cast Survey Mechan by paying 4.
7. Repeat.

This ingenious loop centers around sacrificing Survey Mechan to fuel its own massive ability while utilizing Ashnod's Altar to generate the exact mana needed to recast it. Whenever Survey Mechan hits the graveyard, Mortuary neatly tucks it right back onto the top of your library so you can draw and replay it, turning your hand into a revolving door. Meanwhile, Tormod, the Desecrator watches over your graveyard as cards leave it, spawning Zombie tokens whenever Survey Mechan's trip triggers him. Primal Vigor then doubles down on those token creations, ensuring that sacrificing the resulting horde to Ashnod's Altar yields more than enough colorless mana to sustain the loop indefinitely and bury your opponents in endless damage and card draw.