Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Thermopod + Witch-king, Sky Scourge

Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight

Thermopod

Witch-king, Sky Scourge

How it works

1. Activate Thermopod by sacrificing Witch-king
2. When Witch-king dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
3. Activate Thermopod by sacrificing Witch-king
4. When Witch-king dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
5. Repeat.

This clever loop uses Thermopod as a reliable sacrifice outlet that turns your creatures into a steady stream of red mana. While Witch-king, Sky Scourge naturally returns itself with undying, the real magic happens once Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight transforms into its twilight face and grants persist to your other nontoken creatures. Because the +1/+1 counter from undying and the -1/+1 counter from persist will continuously cancel each other out upon subsequent resurrections, you can sacrifice Witch-king, Sky Scourge over and over again without the counter-based limitations ever shutting down the engine.