Cast Ghouls' Night Out by paying ({3} magic symbol) ({B} magic symbol) ({B} magic symbol) , returning Eternal Witness from your graveyard to the battlefield, and at least two other creatures from your opponents' graveyards to the battlefield under your control.
When Eternal Witness and the creatures enter the battlefield, Blessed Sanctuary triggers once for each creature, and Eternal Witness triggers once.
Resolve the Eternal Witness trigger, returning Ghouls' Night Out from your graveyard to your hand.
Resolve all Blessed Sanctuary triggers, creating that many 2/2 Unicorn creature tokens.
Activate Phyrexian Altar five times by sacrificing Eternal Witness, two creatures your opponents own, and two Unicorns, adding ({3} magic symbol) ({B} magic symbol) ({B} magic symbol) .