Nim Deathmantle + Ashnod's Altar + Tangled Colony + Warstorm Surge

Nim Deathmantle

Ashnod's Altar

Tangled Colony

Warstorm Surge

How it works

1. Activate Ashnod's Altar by sacrificing Tangled Colony, adding CC.
2. When Tangled Colony dies, it and Nim Deathmantle triggers.
3. Resolve the Nim Deathmantle trigger from step 2, causing you to pay 4 to return Tangled Colony from your graveyard to the battlefield, and attach Nim Deathmantle to it.
4. When Tangled Colony enters the battlefield, Warstorm Surge triggers, dealing damage equal to Tangled Colony's power to any target.
5. Resolve the Tangled Colony trigger, creating a 1/1 Rat creature token.
6. When the Rat enters the battlefield, Warstorm Surge triggers, dealing 1 damage to Tangled Colony.
7. Activate Ashnod's Altar by sacrificing the Rat, adding CC.
8. Repeat.