Mikaeus, the Unhallowed + Viscera Seer + Persistent Constrictor

Mikaeus, the Unhallowed

Viscera Seer

Persistent Constrictor

How it works

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