Nim Deathmantle + Krark-Clan Ironworks + Ancient Stone Idol

Nim Deathmantle

Krark-Clan Ironworks

Ancient Stone Idol

How it works

1. Activate Krark-Clan Ironworks by sacrificing Ancient Stone Idol, adding CC.
2. Ancient Stone Idol dies, triggering itself and Nim Deathmantle.
3. Resolve the Ancient Stone Idol trigger, creating a 6/12 Construct artifact creature token.
4. Activate Krark-Clan Ironworks by sacrificing the Construct, adding CC.
5. Resolve the Nim Deathmantle trigger from step 2, causing you to pay 4 to return Ancient Stone Idol from your graveyard to the battlefield, and attach Nim Deathmantle to it.
6. Repeat.