Nim Deathmantle + Ashnod's Altar + Xu-Ifit, Osteoharmonist + Cyclops of Eternal Fury

Nim Deathmantle

Ashnod's Altar

Xu-Ifit, Osteoharmonist

Cyclops of Eternal Fury

How it works

1. Activate Ashnod's Altar by sacrificing another nontoken creature, adding CC.
2. When the creature dies, Nim Deathmantle triggers. Choose not to pay.
3. Activate Xu-Ifit by tapping it, returning a creature from your graveyard to the battlefield.
4. Activate Ashnod's Altar by sacrificing Xu-Ifit, adding CC.
5. When Xu-Ifit dies, Nim Deathmantle triggers, causing you to pay 4 to return it from your graveyard to the battlefield and attach Nim Deathmantle to it.
6. Repeat.

This crafty loop relies on recycling the graveyard using the synergy between Nim Deathmantle and Ashnod's Altar, which together turn any creature's demise into a profit of colorless mana. While Ashnod's Altar fuels the mana requirements for Nim Deathmantle's revival trigger, Xu-Ifit, Osteoharmonist steps in to recur creatures from the graveyard when the Deathmantle's optional payment isn't chosen, and can even sacrifice itself to the Altar to trigger its own revival under the Deathmantle. Meanwhile, Cyclops of Eternal Fury hangs back as part of the board, granting haste to round out your capabilities once the infinite cascade of triggers gets rolling.