Nim Deathmantle + Ashnod's Altar + Ogre Slumlord

Nim Deathmantle

Ashnod's Altar

Ogre Slumlord

How it works

1. Activate Ashnod's Altar by sacrificing another creature, adding CC.
2. The creature dies, triggering Ogre Slumlord and Nim Deathmantle.
3. Resolve the Ogre Slumlord trigger, creating a 1/1 Rat creature token.
4. Activate Ashnod's Altar by sacrificing the Rat, adding CC.
5. Resolve the Nim Deathmantle trigger from step 2, causing you to pay 4 to return the creature from your graveyard to the battlefield, and attach Nim Deathmantle to it.
6. Repeat.