Nim Deathmantle + Ashnod's Altar + Sek'Kuar, Deathkeeper

Nim Deathmantle

Ashnod's Altar

Sek'Kuar, Deathkeeper

How it works

1. Activate Ashnod's Altar by sacrificing another nontoken creature, adding CC.
2. When the creature dies, Sek'Kuar and Nim Deathmantle trigger.
3. Resolve the Sek'Kuar trigger, creating a 3/1 Graveborn creature token with haste.
4. Activate Ashnod's Altar by sacrificing the Graveborn, adding CC.
5. Resolve the Nim Deathmantle trigger from step 2, causing you to pay 4 to return the sacrificed creature from your graveyard to the battlefield, and attach Nim Deathmantle to it.
6. Repeat.

This loop is a masterclass in turning a single sacrifice into a self-sustaining engine, perfectly fueled by Ashnod's Altar providing the exact four mana needed to pay for Nim Deathmantle's resurrection trigger. Whenever your original nontoken creature hits the graveyard, Sek'Kuar, Deathkeeper steps in to sweeten the deal by spawning a Graveborn token, which can be immediately sacrificed to the Altar for more mana or used to churn through your deck's various death triggers. By cycling the primary creature back to the battlefield with the Deathmantle attached while leaving enough colorless mana floating to keep the cycle going, you effortlessly generate an endless storm of entries, exits, and sacrifices.