Chittering Witch dies, triggering Nim Deathmantle, causing you to pay ({4} magic symbol) to return Chittering Witch from your graveyard to the battlefield, and attach Nim Deathmantle to it.
Chittering Witch enters the battlefield, creating at least two 1/1 Rat creature tokens.
Activate Ashnod's Altar by sacrificing a Rat, adding ({C} magic symbol) ({C} magic symbol) .