Ok, you got a pretty good team so far; considering what you are working with here; but it can be a tiny bit better; and I'm going to do the best to help you here (as far as in-game teams go) anyways, this is all opinion; and the in-game stuff never has to be "the best" n,n
1) Sceptile - First step is to get rid of cut, its a horrible HM and its just not good to have. My suggestion is to replace this with pursuit (so you can get some type coverage)
2) Mighteyana - Alright, this one has a decent set for an in-game pokemon, but its still not the best thing to have. If you are wanting a dark type, there is a bunch of better options such as Absol for example. This Pokemon does have intimidate which is a bit handy~
3) Hairyama - It needs some more move typing or maybe something like bulk up. Rock Smash is a horrid move in this generation; so getting rid of that would be good. If you have rock tomb, I'd add that onto his roster; as well as any other moves of diffrent type
4) Alakazam - Suffers from only having one move. Something like a Dusclops can pull off the "only using one-move" tactic as it has a good, and even better support pool to use it.
5)Skarmory - The moves here are good, but throw on spikes to it if you are at the level too.
As for anything else, a good water type would do some help - Lanturn, Starmie, Milotic (if you get one then good luck), and Walrein are good ones to have - A lot of the water types in this generation are either bulky or rather weak.
And if you were to change out any Pokemon at all for any others, here are some thoughts of Pokemon that are really good to add. Aswell as some movesets (only using their learned moves from 1-50)
Gardevior
Psychic - 26
Hypnosis - 51
Calm Mind - 21
Double Team - 11
(Thunderbolt, Shadowball, Shockwave)
Dusclops
Will-O-Wisp - 41
Shadow Punch - 37
Pursuit - 27
Confuse Ray - 23
Lanturn
Surf/Hydro Pump - 50
Confuse Ray - 32
T.Wave - 1
Thunder - TM can be bought
(Thunderbolt and Ice beam)
Walrein
Body Slam - 19
Encore - 3
Surf - HM
Ice Beam(TM), Blizzard, or Aura Beam
Magnton
Tri Attack - 42
Spark - 26
T.Wave - 16
Supersonic - ?
Hope I helped n.n
