Nim Deathmantle + Ashnod's Altar + Rhovanion Rampager

Nim Deathmantle

Ashnod's Altar

Rhovanion Rampager

How it works

1. Activate Ashnod's Altar by sacrificing Rhovanion Rampager, adding CC.
2. When Rhovanion Rampager dies, it and Nim Deathmantle trigger,
3. Resolve the Rhovanion Rampager trigger, creating a creature token.
4. Holding priority, activate Ashnod's Altar by sacrificing a creature token, adding CC.
5. Resolve the Nim Deathmantle trigger, causing you to pay 4 to return Rhovanion Rampager from your graveyard to the battlefield and attach Nim Deathmantle to it.
6. Repeat.