Mikaeus, the Unhallowed + Shilgengar, Sire of Famine + Grazing Kelpie

Mikaeus, the Unhallowed

Shilgengar, Sire of Famine

Grazing Kelpie

How it works

1. Activate Shilgengar 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 Shilgengar ability.
4. Activate Shilgengar 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 Shilgengar ability.
7. Repeat.