Moritte of the Frost + Yahenni, Undying Partisan

Moritte of the Frost

Yahenni, Undying Partisan

How it works

1. Activate Yahenni by sacrificing Moritte of the Frost.
2. When Moritte of the Frost dies, it triggers its persist ability, returning itself to the battlefield as a copy of the creature with persist with two +1/+1 counters and one -1/-1 counter on it.
3. Remove one +1/+1 counter and one -1/-1 counter from Moritte of the Frost as a state-based action.
4. Resolve the activated ability from step 1, giving Yahenna indestructible until end of turn.
5. Repeat.