Wurmcoil Engine + Nim Deathmantle + Krark-Clan Ironworks

Wurmcoil Engine

Nim Deathmantle

Krark-Clan Ironworks

How it works

1. Activate Krark-Clan Ironworks by sacrificing Wurmcoil Engine, adding CC.
2. When Wurmcoil Engine dies, it and Nim Deathmantle trigger.
3. Resolve the Wurmcoil Engine triggers, creating a 3/3 Wurm token with deathtouch and a 3/3 Wurm token with lifelink.
4. Holding priority, activate Krark-Clan Ironworks by sacrificing a Wurm token, adding CC.
5. Resolve the Nim Deathmantle triggers, causing you to pay 4 to return Wurmcoil Engine from your graveyard to the battlefield, and attach Nim Deathmantle to it.
6. Repeat.