I played GK's for a while and grew to love them, they're pretty fun and toolbox like crazy. You're running too many monsters though, and your trap line-up could use some work.
All you need as far as GK monsters go is Commandant, Recruiter, Descendant, and Spy. 3 of each of course, and you can tech in 1 Assailant and 1 Guard, I usually side guard because he's a good defensive monster and gets over a lot of problems, but I mostly play aggressive with GKs.
Good tech cards include Thunder King Rai-oh for a nice first turn stun set up (commandant search, summon thunder king, play necrovalley, set 2 backrow, and it will take a lot for the opponent to get over without a heavy storm), Effect veiler works nice and with those 2 being light and having dark GK monsters, you can run BLS. Also I'd use Malefic Cyber End Dragon over Stardust. Sure, stardust protects your field spell, but you have 3, and 3 searchers for it, and you have 3 searchers for your searchers. You should have no problem getting a necrovalley on board. I only run 1 Malefic as well since I run 2 other boss monsters, BLS and Dark Armed Dragon. BLS is still kind of meh in this deck though and can be dead a lot. he's been a recent addition and I didn't test him much since I've been busy with Blackwings.
Why Dark Armed Dragon? Can't use his eff cuz of necrovalley? Doesn't matter. He's still a free 2800 beater, and like I said you'll have plenty of options to get to your necrovalleys. So, if you wanna make a DaD play for game, but you have a necrovalley face-up, simply destroy it and play ur 2nd or 3rd necrovalley face-down. Summon DaD and go ham. then flip valley up afterwards if necessary.
Also you have to consider you won't always have Necrovalley face-up. MST is at 3, you'll have times where it won't be present. Instead of immediately playing your 2nd or 3rd one, pop down a DaD or BLS, and also add Monster Reborn to your deck. People say its contradicting, but it's not if you play smart. Just like how Thunder King Rai-Oh and Duality contradict, people still play them in the same deck, just play them separately. This also forces you to play a bit more conserved, which some players struggle with.
Your spells are a bit messy too. First lets start by removing Card Destruction, Terraforming, Magical Dimension(optional, its a good card for GKs I'll admit and it works well with recruiter, but personally I don't find it necessary), and what is that green background white stick lookin thing? I've never seen it before, and probably for a good reason.
not sure why you run card destruction at all really, it doesn't trigger any of your monsters, and Royal Tribute is pretty much GK's OP version of it.
Terraforming is wasted space considering commandant does the same thing for you and more.
I'd consider running 3 GK's Steele. A lot of people disagree with me on this (just as most disagree with me about DaD, BLS, and Monster Reborn, but they win me games all de time), but trust me, having so much search ability with spy, recruiter, AND commandant makes you run through monsters fast, and steele gives you such huge advantage early, mid, and late game. You want it in your hand as much as possible, so run 3.
Run 2 Dualities, good search card and GK's don't really special summon all that much.
You could also try to make room for 2 or 3 MSTs. It's good for getting Necrovalley off the board to make BLS/monster reborn/DaD plays if you think you can go for game or they're your only options in hand.
For traps, Rite of Spirit is meh, you have steele to bring them back to your hand which imo is better because that's less cards you have to Set/commit to the board. I personally don't like it, but it's not a terrible choice so that you can do what you want with, your preference.
Magician's Circle is unnecessary if you run less monsters. You're gonna be searching like crazy and run low on monsters, so it'll be dead late game and especially in a tight situation. When you're low on card presence and playing defensively, Magician's Circle is quite possibly the worst top deck possible.
Bottomless Trap Hole is great this format so I'd suggest running 2. Also, you're running darks that can hit above 2000 atk. Test out Deck Devastation Virus, it kills a lot of decks this format as well. Other traps you could run include Fiendish Chain, Starlight Road, and compulsory Evac. device.
WALL O' TEXT! sorry, guess I like GK's more than I thought lol.