You control a permanent that can tap to produce at least ({U} magic symbol) .
Steps
Activate the mana-producing permanent by tapping it, adding ({U} magic symbol) .
Activate Fatestitcher's unearth ability by paying ({U} magic symbol) , returning it from your graveyard to the battlefield and giving it haste until end of turn.
Activate Fatestitcher by tapping it, untapping the mana-producing permanent.
Activate Viscera Seer by sacrificing Fatestitcher.
Choose to exile Fatestitcher using Void Maw's replacement effect instead of Fatestitcher's.
Resolve the Viscera Seer ability, causing you to scry 1.
Activate Void Maw by putting Fatestitcher from exile into your graveyard, giving Void Maw +2/+2 until end of turn.