Mortuary + Ashnod's Altar + Memnite + Gwenom, Remorseless

Mortuary

Ashnod's Altar

Memnite

Gwenom, Remorseless

How it works

1. Activate Ashnod's Altar by sacrificing Memnite
2. When Memnite dies, Mortuary triggers, putting Memnite from your graveyard onto the top of your library.
3. Cast Memnite from the top of your library by paying 0 life.
4. Repeat.

This ingenious loop turns a free artifact creature into an infinite engine by leveraging Mortuary's mandatory library-stacking whenever a creature hits the graveyard. Ashnod's Altar provides the sacrifice outlet to generate a steady stream of colorless mana while sending your creature straight to the yard. Meanwhile, Gwenom, Remorseless grants you the crucial ability to play cards directly from the top of your library. Because Memnite costs zero mana, Gwenom's alternative payment requirement drops the life cost to zero as well, allowing you to recast the free artifact creature over and over again without ever running out of resources.