When Spectral Arcanist enters the battlefield, it and Healer of the Pride trigger.
Resolve the Healer of the Pride trigger, causing you to gain 2 life.
Holding priority, activate Lord of the Forsaken's second ability twice by paying 2 life, adding ({C} magic symbol) ({C} magic symbol) that can only be spent to cast a spell from your graveyard.
Activate Skirge Familiar by discarding Corpse Dance, adding ({B} magic symbol) .
Activate Lord of the Forsaken's first ability by paying ({B} magic symbol) and sacrificing Spectral Arcanist, causing target player to mill three cards.
Resolve the Spectral Arcanist trigger from step 2, causing you to pay ({2} magic symbol) to cast Corpse Dance from your graveyard with buyback.
Resolve Corpse Dance, returning Spectral Arcanist from your graveyard to the battlefield, and returning Corpse Dance to your hand.