This deck is pretty wild however I'm slightly unsure about some things (bottom of description)
Phytexian Obliterator - Value + 4 Devotion + Anti-burn + Permanent removal.
Crypt Ghast - Basically doubles mana + Extort
Vampire Nighthawk - Answer for flyers + Lifegain + 2 Devotion + Deathtouch
Gray Merchant - Life gain + Win Con + 2 Devotion
Nantuko Shade - 2 Devotion + Pump up (Nice combo with Crypht Ghast and Shrine to Nyx)
Nightveil Specter - 3 Devotion + Flyer + Ability as a bonus.
Phytexian Metamorph - This card is so useful in so many ways. (Nice combo with Gray merchant!)
Spellskite - Basically counters pump ups + Protects other creatures
Demonic Tutor - Wow a 2 drop draw any card you need. Basically adds a full play set of any ther card in the deck!
Dismember - Removal + Value
Profane Command - Win Con + Removal + Brings back a creature + Evasion
Ereobos - Draw power + Value + Indestructible - Devotion shouldn't be an issue to make him a creature
Is there something missing or could anything be replaced by something better? The way this deck stands right now everything fits in pretty well. It'd be pretty difficult to find something that could take another cards place and add more value while keeping consistency.