You control an additional nontoken non-Spirit creature.
Steps
Activate
Ashnod's Altar by sacrificing a nontoken non-Spirit creature, adding ({C} magic symbol) ({C} magic symbol) .
When the creature dies,
Requiem Angel and
Nim Deathmantle triggers.
Resolve the
Requiem Angel trigger, creating a 1/1 Spirit creature token.
Activate
Ashnod's Altar by sacrificing the Spirit, adding ({C} magic symbol) ({C} magic symbol) .
Resolve the
Nim Deathmantle trigger from step 2, causing you to pay ({4} magic symbol) to return the non-Spirit creature from your graveyard to the battlefield, and attach