Activate Ashnod's Altar by sacrificing Caller of the Claw, adding CC.
Caller of the Claw dies, triggering Nim Deathmantle, causing you to pay 4 to return Caller of the Claw from your graveyard to the battlefield, and attach Nim Deathmantle to it.
Caller of the Claw enters the battlefield, creating a 2/2 Bear creature token for each nontoken creature that died under your control this turn.
Activate Ashnod's Altar by sacrificing a Bear, adding CC.