Mikaeus, the Unhallowed + Living Death + Ashnod's Altar + Blood Pet + Eternal Witness

Mikaeus, the Unhallowed

Living Death

Ashnod's Altar

Blood Pet

Eternal Witness

How it works

1. Activate Blood Pet by sacrificing it, adding .
2. When Blood Pet dies, its undying ability triggers, returning it to the battlefield from your graveyard with a +1/+1 counter on it.
3. Activate Blood Pet by sacrificing it, adding .
4. Activate Ashnod's Altar twice by sacrificing Eternal Witness and Mikaeus, adding CCCC.
5. Cast Living Death by paying 3, causing each player to exile all creature cards in their graveyards, sacrifice all creatures they control, then put all cards exiled this way onto the battlefield.
6. When Eternal Witness enters the battlefield, it triggers, returning Living Death to your hand from your graveyard.
7. Repeat.