Mikaeus, the Unhallowed + Luminous Broodmoth + Yahenni, Undying Partisan

Mikaeus, the Unhallowed

Luminous Broodmoth

Yahenni, Undying Partisan

How it works

1. Activate Yahenni by sacrificing the creature.
2. When the creature dies, its undying ability triggers if it didn't have a +1/+1 counter, and Luminous Broodmoth triggers if the creature didn't have flying.
3. Resolve the undying trigger, if applicable, returning the creature from your graveyard to the battlefield with a +1/+1 counter on it.
4. Resolve the Luminous Broodmoth trigger, if applicable, returning the creature from your graveyard to the battlefield with a flying counter on it if the creature is still in your graveyard.
5. Resolve the Yahenni ability.
6. Repeat.