Nim Deathmantle + Ashnod's Altar + Garrison Cat

Nim Deathmantle

Ashnod's Altar

Garrison Cat

How it works

1. Activate Ashnod's Altar by sacrificing Garrison Cat, adding CC.
2. When Garrison Cat dies, it and Nim Deathmantle trigger,
3. Resolve the Garrison Cat 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 Garrison Cat from your graveyard to the battlefield and attach Nim Deathmantle to it.
6. Repeat.