Activate Krark-Clan Ironworks by sacrificing Precursor Golem, adding CC.
When Precursor Golem dies, Nim Deathmantle triggers, causing you to pay 4 to return Precursor Golem from your graveyard to the battlefield, and attach Nim Deathmantle to it.
When Precursor Golem enters the battlefield, its first ability triggers, creating two 3/3 Golem creature tokens.
Activate Krark-Clan Ironworks by sacrificing a Golem, adding CC.