Activate Ashnod's Altar by sacrificing Pia and Kiran Nalaar, adding CC.
When Pia and Kiran Nalaar dies, Nim Deathmantle triggers, causing you to pay 4 to return Pia and Kiran Nalaar from your graveyard to the battlefield and attach Nim Deathmantle to it.
When Pia and Kiran Nalaar enters, it triggers, creating two creature tokens.
Activate Ashnod's Altar by sacrificing a creature token, adding CC.