Activate Ashnod's Altar by sacrificing the creature with Nim Deathmantle attached, adding CC.
The creature dies, triggering Nim Deathmantle and One with the Kami.
Resolve the One with the Kami trigger, creating at least two 1/1 Spirit creature tokens.
Activate Ashnod's Altar by sacrificing a Spirit token, adding CC.
Resolve the Nim Deathmantle trigger from step 2, causing you to pay 4 to return the creature from your graveyard to the battlefield, and attach Nim Deathmantle to it.