Sedgemoor Witch triggers, creating a 1/1 Pest creature token.
Resolve Cloudshift, blinking Skullwinder.
Skullwinder enters the battlefield, returning Cloudshift from your graveyard to your hand and causing target opponent to return a card from their graveyard to their hand.
Activate Phyrexian Altar by sacrificing the Pest, adding ({W} magic symbol) .