Mikaeus, the Unhallowed + Warren Soultrader + Dross Harvester

Mikaeus, the Unhallowed

Warren Soultrader

Dross Harvester

How it works

1. Activate Warren Soultrader by paying 1 life and sacrificing the persist creature.
2. When the persist creature dies, its persist ability triggers if it didn't have a -1/-1 counter on it, and its undying ability triggers if it didn't have a +1/+1 counter on it. Dross Harvester also triggers regardless.
3. Resolve the Dross Harvester trigger, causing you to gain 2 life.
4. Resolve the persist trigger, if applicable, returning the creature from your graveyard to the battlefield with a -1/-1 counter on it.
5. Resolve the undying trigger, if applicable, returning the creature from your graveyard to the battlefield with a +1/+1 counter on it.
6. Resolve the Warren Soultrader ability, creating a Treasure token.
7. Repeat