2015 Blackwings

Looks similar to 2014 BWz except for a couple of cards.

Well blackwings have everything unlimited, so I am trying to make the optimal build

Looks nice to me, maybe Soul Charge?

-1 Icarus Attack
+1 Back Sonic

Done.

you either run 3 Icarus Attack or you run none, so nop.

Having 3 just clogs the deck and S/T Zone, 2 is all that you'll ever need.

Black Sonic, on the other hand, is needed at least 2 if you're expecting it to be any good. It's the best defensive card the Blackwings could ever dream of, it needs to be used more.

You want to make an optimal build? Okay.

Well firstly I have literally no idea why you aren't running 3 shura. It's arguably the best blackwing main deck monster you have, combos so well with kalut and is just the center of the blackwing engine. 

Sirocco should never go above 1. It's effect isn't all that great but does have some utility in the deck and its kinda hard to bring out at times, not to mention opening multiples would just be straight awful, so it'd be confortable at 1.

Kris seems sub-par. Blackwings function fine without it and it could cause clogging of opening hands especially with the extra sirocco. I'd remove both copies.

Cards for black feathers is just a straight up bad card with no upside other than making use of the dead sirocco you'll be drawing a lot. The extra draw power isn't needed with allure, whirlwind and duality already there and you can use the space a lot better.

Raigeki is a bad card. Most of your matchups will be shaddoll/BA/qli and none of them care about raigeki, the former two actually go plus if you use it on most field they can put up. Raigeki is a side deck card for rogue decks and tellars at best.

Lastly, you run 3 MST if you're running it at all. No exceptions. Oh and 3 gale just isn't needed, and COTH is in no way comparable with soul charge. If you're only running one graveyard revival s/t and you're not playing artifacts you play soul charge.

So in conclusion I'd advise testing these changes:

-1 Sirocco
-2 Kris
-1 Gale
-1 CoTH
-1 Raigeki
-1 Cards for black feathers
- that randy trap tech at the end

+2 shura
+1 MST
+1 Soul charge
+2/3 vanity's emptiness - Staple card right now and provides a tough-to-break lock with master key beetle
+1 Book of Moon
+1 (if you went for 2 copies of vanity's) foolish burial for vayu/zephyros