A tempo deck I'm looking to perfect based around Duskmantle Seer. I am looking for any and all suggestions on this deck. I'm not looking however, to make it black devotion, i know it would be very easy to but please don't tell me Gray Merchant of Asphodel would be good in it, cause i know he would but that's not the point. I also don't want anything over 3 costing in the whole deck other than the Duskmantle Seers.
FULL CARD RUNDOWN:
Thoughtseize : No need for explanation, a top card in all of magic nevermind just standard.
Cloudfin Raptor : Adds a devotion to blue as well as growing into a bigger threat. Also a fine target to tap early to ramp slightly with Springleaf Drum.
Pain Seer (removed) : A decent little beater who is gonna be accelerating me by drawing cards, evolving Cloudfin Raptor and constantly taking 2 damage bites out of my opponents ankles. Once he cant beat in anymore Springleaf Drum is there to keep tapping him if need be, even if he cant swing.
Nightveil Specter : steal your opponents cards, great devotion, just a great value creature. Also once again evolves Cloudfin Raptor.
Ashiok, Nightmare Weaver : Another card to steal your opponents cards and play them, a very scary strong planeswalker. Adds a devotion to blue as well just as a kicker.
Thassa, God of the Sea : A recent addition to the deck however just so great for the deck with scry to avoid damage from Duskmantle Seer and Pain Seer and unblockability when needed.
Duskmantle Seer : The feature card of the deck, a 4/4 for 4 in the air which is great on its own, the deck built around everything other than himself being 3 cost or less however my opponent is not so lucky. he is the reason for Time Ebb and Dimir Charm as I can just throw something on top of their library for a huge smack of damage. (possibly even game winning damage)
Thank you in advance for your input!
Cards I am considering very seriously:
Whip of Erebos: the lifelink may be what i really need for this deck to really shine but more play testing post-removal of Pain Seer is required before i can consider a 4 cost card.
Pack Rat: debating Pack Rat over returned phalanx. Would like feedback here as well.
Vortex Elemental : can throw a much larger card back into the opponents deck and is only 1 cost so not damaging when it shows back up off of Pain Seer or Duskmantle Seer
Crypsis : A very cool card especially combined with inspired on Pain Seer can make for a very favorable trade AND draw at the same time.