Mikaeus, the Unhallowed + Carrion Feeder + Glen Elendra Archmage

Mikaeus, the Unhallowed

Carrion Feeder

Glen Elendra Archmage

How it works

1. Activate Carrion Feeder by sacrificing Glen Elendra Archmage.
2. When Glen Elendra Archmage dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Resolve the Carrion Feeder ability.
4. Activate Carrion Feeder by sacrificing Glen Elendra Archmage.
5. When Glen Elendra Archmage dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
6. Resolve the Carrion Feeder ability.
7. Repeat.