Activate Ashnod's Altar by sacrificing Cultivator of Blades, adding CC.
Cultivator of Blades dies, triggering Nim Deathmantle, causing you to pay 4 to return Cultivator of Blades from your graveyard to the battlefield, and attach Nim Deathmantle to it.
Cultivator of Blades enters the battlefield, creating two 1/1 Servo creature tokens.
Activate Ashnod's Altar by sacrificing a Servo, adding CC.