Keiga, the Tide Star + Nim Deathmantle + Ashnod's Altar

Keiga, the Tide Star

Nim Deathmantle

Ashnod's Altar

How it works

1. Whenever an opponent controls a creature, activate Ashnod's Altar by sacrificing Keiga, adding CC.
2. When Keiga dies, it and Nim Deathmantle trigger.
3. Resolve the Keiga trigger, causing you to gain control of a creature an opponent controls.
4. Activate Ashnod's Altar by sacrificing the creature you gained control of in step 3, adding CC.
5. Resolve the Nim Deathmantle trigger from step 2, causing you to pay 4 to return Keiga from your graveyard to the battlefield, and attach Nim Deathmantle to it.
6. Repeat as desired and/or whenever a creature enters the battlefield under an opponent's control.

This clever loop turns Ashnod's Altar into a devastating engine for total board control by weaponizing Keiga, the Tide Star's death trigger. By sacrificing Keiga to the Altar, you generate the exact amount of mana needed to fund Nim Deathmantle's revival ability—while simultaneously triggering Keiga to steal an opponent's creature. You can then feed that stolen creature right back into Ashnod's Altar to pay for the Deathmantle's resurrection cost, bringing Keiga back to the battlefield ready to repeat the cycle.