Nim Deathmantle + Ashnod's Altar + Eldrazi Skyspawner

Nim Deathmantle

Ashnod's Altar

Eldrazi Skyspawner

How it works

1. Activate Ashnod's Altar by sacrificing Eldrazi Skyspawner, adding CC.
2. When Eldrazi Skyspawner dies, Nim Deathmantle triggers, causing you to pay 4 to return Eldrazi Skyspawner from your graveyard to the battlefield and attach Nim Deathmantle to it.
3. When Eldrazi Skyspawner enters, it triggers, creating a creature token.
4. Activate Ashnod's Altar by sacrificing a creature token, adding CC.
5. Repeat.