Mortuary + Ashnod's Altar + Vizier of the Menagerie

Mortuary

Ashnod's Altar

Vizier of the Menagerie

How it works

1. Activate Ashnod's Altar by sacrificing the nontoken creature, adding CC.
2. When the creature dies, Mortuary triggers, putting the creature from your graveyard onto the top of your library.
3. Cast the creature by paying its mana cost.
4. Repeat.

This loop turns any creature into an endless engine of life and death, fueled smoothly from the top of your deck. You begin by sacrificing your creature to Ashnod's Altar to generate the colorless mana you'll need, which simultaneously triggers Mortuary to place that exact creature right back on top of your library. Thanks to Vizier of the Menagerie, you can peek at that top card at any time and immediately cast it again using the mana you just generated, bypassing normal hand restrictions. Repeating this cycle creates an infinite loop of leaves-the-battlefield, entry, and death triggers while generating boundless colorless mana.