Activate Ashnod's Altar by sacrificing Cultivator of Blades, adding ({C} magic symbol) ({C} magic symbol) .
Cultivator of Blades dies, triggering Nim Deathmantle, causing you to pay ({4} magic symbol) 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 ({C} magic symbol) ({C} magic symbol) .