Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Iron League Steed + Yahenni, Undying Partisan

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

Iron League Steed

Yahenni, Undying Partisan

How it works

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

This loop hinges on a clever mechanical interaction between counter-placement and recursion, transforming Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight into an engine of endless sacrifices. By using Yahenni, Undying Partisan to repeatedly sacrifice Iron League Steed, you trigger the persist ability granted by Isilu's back face, which brings the Steed back with a -1/-1 counter. Fortunately, Iron League Steed's fabricate ability immediately counters this drawback by placing a +1/+1 counter on it, effectively neutralizing the -1/-1 counter through state-based actions and leaving the Steed ready to be sacrificed all over again.