Be'lakor, the Dark Master + Dread Slaver + Xenograft + Ashnod's Altar

Be'lakor, the Dark Master

Dread Slaver

Xenograft

Ashnod's Altar

How it works

1. Cast Dread Slaver by paying 3.
2. When Dread Slaver enters the battlefield, Be'lakor's second ability triggers, causing Dread Slaver to deal damage equal to its power to itself.
3. Activate Ashnod's Altar by sacrificing Dread Slaver, adding CC.
4. When Dread Slaver dies, it triggers, returning itself from your graveyard to the battlefield.
5. Repeat from step 2.

This clever loop turns your own horrors into a self-sustaining engine by making every creature a Demon through Xenograft. Whenever Dread Slaver enters the battlefield, Be'lakor, the Dark Master triggers to deal damage equal to the Slaver's power to itself, which conveniently sets up its own demise. You then feed that dying Dread Slaver to Ashnod's Altar for colorless mana, and the Slaver's own lingering damage-dealer trigger rescues it right back to the battlefield as a black Zombie ready to repeat the cycle.