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