Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Yahenni, Undying Partisan + Cayth, Famed Mechanist

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

Yahenni, Undying Partisan

Cayth, Famed Mechanist

How it works

1. Activate Yahenni by sacrificing Cayth.
2. When Cayth dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When Cayth enters, its fabricate ability triggers, putting a +1/+1 counter on it.
4. Resolve the Yahenni ability.
5. Repeat.

This elegant loop turns a simple sacrifice into a self-sustaining engine by cleverly manipulating counters and creature types. With the front side of Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight transformed into its Isilu state, your nontoken creatures gain persist, allowing Cayth, Famed Mechanist to return to the battlefield after being fed to Yahenni, Undying Partisan's sacrifice ability. Because Cayth and other nontoken creatures also grant themselves fabricate 1 thanks to Cayth's static ability, each time Cayth enters the battlefield, the resulting +1/+1 counter immediately neutralizes the -1/+1 counter from persist. Meanwhile, every iteration pumps Yahenni, Undying Partisan larger and triggers all your death, sacrifice, and entry effects endlessly.