Nim Deathmantle + Ashnod's Altar + Mitotic Slime

Nim Deathmantle

Ashnod's Altar

Mitotic Slime

How it works

1. Activate Ashnod's Altar by sacrificing Mitotic Slime, adding CC.
2. When Mitotic Slime dies, it and Nim Deathmantle trigger,
3. Resolve the Mitotic Slime trigger, creating two 2/2 Ooze creature tokens.
4. Holding priority, activate Ashnod's Altar by sacrificing an Ooze, adding CC.
5. When the Ooze dies, it triggers, creating two 1/1 Ooze creature tokens.
6. Resolve the Nim Deathmantle trigger, causing you to pay 4 to return Mitotic Slime from your graveyard to the battlefield and attach Nim Deathmantle to it.
7. Repeat.