I'm pretty sure I want to remove the 4x Nightveil Specter and 2x Chromatic Lantern . These will be replaced with 3x Ultimate Price and 3x Tragic Slip . I still need to cut some extra cards, but am not sure where.

Nightveil Specter is dictating the Chromatic Lantern 's presence, and I think there are better creatures at the 3-drop spot for what I'm trying to do, if I need them. Namely, Vampire Nighthawk and potentially Selhoff Occultist , which fits the plan. Nightveil Specter is easier on the mana, and gives some potential utility, but the Vampire Nighthawk is a better body, and Selhoff Occultist fits the general plan better - especially when paired with a board sweeper like Mutilate .

I think the biggest issue here is a lack of direction and staple cards. Staples in a typical current Dimir deck that you don't have are 4x Mind Grind , either 4x Deathcult Rogue or 4x Invisible Stalker , and between 2 and 4 card:Rogue's Passage, 2 to 4 Ultimate Price or Murder . I agree with removing Nightveil Specter and Chromatic Lantern , also consider removing Liliana of the Dark Realms , Mutilate and Realmwright . Vampire Nighthawk is a very solid 3 drop, I would suggest 4 of them.Selhoff Occultist simply isn't as good as it should be, consider 2 at most.

On a side note, notice the awesome combo with Duskmantle Guildmage and Mindcrank !

Thanks for the comment! I responded in my update above, but a number of those things are right on point.

Mutilate is an obvious sideboard target, but I play against so many aggro decks that it seems hard not to keep in the main board. Duskmantle Guildmage and Mindcrank looks awesome. That's a fun catch.

-1 Warped Physique
-2 Thought Scour
+1 Wight of Precinct Six
+2 Mind Sculpt