Mikaeus, the Unhallowed + Bloodflow Connoisseur + Grazing Kelpie

Mikaeus, the Unhallowed

Bloodflow Connoisseur

Grazing Kelpie

How it works

1. Activate Bloodflow Connoisseur by sacrificing Grazing Kelpie.
2. When Grazing Kelpie 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 Grazing Kelpie.
5. When Grazing Kelpie 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.