Hello,as yesterday i will try to give you my opinion on the whole team and on the mon's sets.
Same for yesterday,dark isn't that good as monotype,but well better than ice and he has some nice mons.(Most viables are flying and steel,but also fairy are water are very strong)
Team
-Good mons,pretty bulky with umbreon and tyranitar,strong sweepers.
Anyway you miss Urshifu-S that imo is the best dark mon along with Mandibuzz,so i would use them.
I would replace Zoroark who isn't that "wow" and Krookodile or Tyranitar.
Krookodile is your setter but you can use also Tyranitar as a setter and imo he is way better.
Your team is way to weak to Fairy,Urshifu could be more helpful with Poison Jab and good speed,and i think you have to use scarf Hydreigon for more chance to win against Fairys.
Sets
-Sableye
Lagging tail ? Why would u use that ? There is kinda no sense to use it on a prankster mon like Sableye and in generale you don't use it that much.
Moves are good,i would invest the EVs in max SpDef and use Will-o-wisp for physical mons,cause it also has priority and it could work better like this imo.
I would replace it with fake out,that deals a really little amount of damage.
-Hydreigon
Why would u use Heavy-Duty Boots ? he isn't weak to rocks and he isn't a pivot so that makes no sense,use instead Leftovers or Life orb.
You could also try to use Choice Scarf and 4 attack moves.(Flash cannon,Draco meteor,Dark Pulse,Flamethrower/Earth power) Flamethrower is better for Bug-Types.
You absolutely need to use Flash Cannon cause your team is weak to Fairy Types.
You can replace Defog and use it on Mandibuzz,if u will put it,cause it is a very strong mon.
I would use 252 EVs in Speed cause he can reach a decent Speed.
Remember that Dark type is very weak to Fairy,and in the high ladder Fairy Teams are really common,so i would use him with Choice scarf to allow you to get some nice kills with Flash Cannon.
-Zoroark
As i said,i don't love this mon but i can't say he is bad and he also has a good moveset,the only move you need to change is Crunch.
You need to use Dark pulse,cause Crunch is physycal.
-Tyranitar
Tyranitar with Sand Stream and due his Rock Type,he already gets a boost in Special Defense.
I would then replace Assault Vest with Rocky Helmet or Leftovers to use him as a setter.
His EVs are good how they are,i would change Avalanche and Brick Break with Stealth Rock and Thunder Wave.
-Umbreon
Good mon but he is too weak to Taunt.
Also substitute isn't that helpful,so i would use Knock off/Foul Play.
Foul play is much better with Calm Nature,so u will have a good bulk against Special Mons and against Physical ones you will use Foul play.
-Krookodile
That set is kinda strange,if u want to use him then go for intimidate and Leftovers / Rocky helmet,with Knock off and Earthquake.
Or you can also use him with Choice Scarf,same EVs,Moxie ability, with Close Combat,Earthquake,Knock off,Stone Edge.
I would put Mandibuzz and Urshifu as i said,and if u "fix" the sets then it should look like this
I haven't talked about Fightning or Bug types cause there isn't much that u can do.
Mandibuzz and Hydreigon can be useful against Bug Types,along with Urshifu-S.
Against Fightning you actually can't do that much.
Another Mon that u can try to use is Galarian Moltres as a setup sweeper with Agility,Weakness Policy and Berserk.
It can be very lethal in low ladder and he is also good in the high ladder.
I hope i was helpful.
