Mikaeus, the Unhallowed + Kithkin Spellduster + Bloodflow Connoisseur

Mikaeus, the Unhallowed

Kithkin Spellduster

Bloodflow Connoisseur

How it works

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