Mortuary + Ashnod's Altar + Mm'menon, the Right Hand

Mortuary

Ashnod's Altar

Mm'menon, the Right Hand

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 infinite loop turns a creature into a self-sustaining engine by letting Ashnod's Altar sacrifice it for colorless mana while simultaneously triggering Mortuary to stack the creature right back onto the top of your library. From there, Mm'menon, the Right Hand steps in as a vital enabler; its static ability lets you look at the top card of your library at any time and cast it directly from there as an artifact spell (or creature spell, depending on its typeline), bypassing your hand entirely. Because Mm'menon also grants your artifacts the ability to tap for blue mana restricted to spells cast from anywhere other than your hand, the infrastructure you need to recast your looped threat is entirely self-contained.