Ghired dies, triggering Nim Deathmantle, causing you to pay ({4} magic symbol) to return Ghired from your graveyard to the battlefield, and attach Nim Deathmantle to it.
When Ghired enters the battlefield, its first ability triggers, creating a 4/4 Rhino creature token.
Activate Ashnod's Altar by sacrificing the Rhino, adding ({C} magic symbol) ({C} magic symbol) .