That's pretty nice. Your curve seems to jump from 3cmc to 6cmc pretty quickly, relying on a bunch of weaker creatures to get you to your big flyer (better hope your opponent doesn't have a murder or pacify). But I'm sure that when it all comes together those Nightmares can probably close out games pretty quickly. I'm sure your opponents are probably wasting a lot of removal early on the Nighthawks and Specters, so maybe you are able to safely pull Nightmare out lategame.
You don't have very much removal but atleast you can recycle it.
I got one slot with 4
tormented Soul and 4
Goblin War Paint with a bunch of Shock and Murder. I think I have a few Giant Scorpions and maybe a Nighthawk in there for defense. It really takes people by surprise, especially when they remove the first Tormented Soul and a second comes out the next turn already swinging.
I also have a mono white deck with 6 Master of Diversion and a couple Honor of the Pure which seems to drive my opponents nuts!
I'm just over the whole Mono-Black or U/B decks in sealed. I only have 1 U/B deck and it doesn't really play like any other U/B deck I've seen. it's not so much about delaying the game so I can pull out big demons, it's a flying beats deck that uses Phantasmal Dragon, a couple nighthawks and bloodhunters but finishes with Rune-Scarred and Windreader Sphinx. Several Divinations and Blood Pacts help me get there and the deck ends up crushing people thru pure card advantage. I'm not sure if I prefer this or my U/R dragon deck in terms of flying beats. They're both fun, but Dragons leans more on Unsummon and Frostbreath to get my creatures thru while holding defense with Fog Banks.. If they aren't running flyers then Unsummon and Frostbreath become defensive too, making it pretty hard to hit me.
But my favorite are the R/G aggro decks. I just love the Beast/Advocate combo and everyone is so ate up on Murder/Assassinate that they forget that red has a lot of direct damage removal in Shock, Flames of the Firebrand and Meteor. Add Hunt The Weak and you have plenty of removal and big 'ol stompy creatures. Gotta run those spiders for flying defense though.
Edit: What system do you play on? I'm on PS3 and Max_uk is the only forum member I can get to play sealed with me.