What are some improvements I could make on this team?

[KoolKat vs. Lucas]

Rate this team because I haven't been defeated yet-

Mewtwo level 100
Bold nature
stats-
attack 239
def 214
sp atk 328
sp def 220
speed 277
ability pressure
moves-
psycho cut
aura sphere
psychic
guard swap

Dialga level 70
adamant nature
stats-
atk 195
def 179
sp atk 206
sp def 162
speed 147
Ability pressure
moves-
roar of time
heal block
earth power
slash

Scizor level 49
gentle nature
atk 147
def 105
sp atk 73
sp def 107
spd 83
ability swarm
moves-
iron head
x-scissor
night slash
quick attack


Startaptor level 70
adamant nature
stats-
atk 227
def 117
sp atk 92
sp def 85
spd 179
ability indimidate
moves-
fly
aerial ace
defog
close combat

Houndoom level 70
relaxed nature
stats-
atk 152
def 105
sp atk 180
sp def 188
spd 143
ability early bird

Lucario level 36
docile nature
stats-
atk 89
def 66
sp atk 91
sp def 58
spd 75
ability steadfast

The Lucario/Scizor are still in training.

 

[blue]

You have generally a good group of Pokémon.
To start, with Scizor I'd replace Quick attack with a tactical/stat boosting move i.e Iron Defence or Swords Dance, Quick Attack is nowhere near as powerful as the other 3 moves. Staraptor, I recommend replacing defog with something strong like Hyper Beam, or U-Turn or you could go with something like Captivate. Dialga & Mewtwo are fine as they are and as for Lucario & Houndoom I'm not sure considering you haven't noted down their movepool, hope this helped!

 

[Ho-Oh]

Adding to what the above user said, you're better off with bullet punch > iron head, although the latter is stronger, you'll generally come to love the added priority in regards to Scizor and for STAB, replace x-scissor with u-turn, since switching out on possible threats is better than just gaining a slight difference of 10 in power and not being able to switch out easily. Psychic and ghost types aren't usually that much of a threat to Scizor so try Superpower or Brick Break instead (depending on whether you're using Platinum and up, or Brick Break). Swords Dance is generally more useful since it has pretty good defences and you'd rather boost the attack so it can all-out kill whatever it's facing.

For Staraptor, you don't really need Fly AND Aerial Ace, especially since Fly doesn't always have 100% accuracy and that's a bad thing. You could use the extra move slot (aka removing fly) for something like whirlwind incase the opponent boosts their stats or something (doubtful in-game but your team may be wifi-based...?) and brave bird, although damaging, can be more useful than aerial ace in terms of strength. :x However, I'm afraid I'm going to have to disagree with the poster on hyper beam, since it generally leaves you wide open to the opponent setting up on you and basically gives them a free turn, it's really not worth it in the end. :(

On Dialga, try Dragon Pulse or Draco Meteor, both are STAB attacks and special, so it fits right into what you want. It just depends on whether you're willing to keep it in for a while or not, though. The reason why you shouldn't use Roar of Time is basically for the same reason you wouldn't use Hyper Beam, leaving you immobile for a turn, which you really don't want. Slash is generally not a great attack, so you could go with any of the various special attacks of other types, really. Just anything but a physical normal type attack.

Have fun fixing up this team either way!

 

[KoolKat vs. Lucas]

Adding to what the above user said, you're better off with bullet punch > iron head, although the latter is stronger, you'll generally come to love the added priority in regards to Scizor and for STAB, replace x-scissor with u-turn, since switching out on possible threats is better than just gaining a slight difference of 10 in power and not being able to switch out easily. Psychic and ghost types aren't usually that much of a threat to Scizor so try Superpower or Brick Break instead (depending on whether you're using Platinum and up, or Brick Break). Swords Dance is generally more useful since it has pretty good defences and you'd rather boost the attack so it can all-out kill whatever it's facing.

For Staraptor, you don't really need Fly AND Aerial Ace, especially since Fly doesn't always have 100% accuracy and that's a bad thing. You could use the extra move slot (aka removing fly) for something like whirlwind incase the opponent boosts their stats or something (doubtful in-game but your team may be wifi-based...?) and brave bird, although damaging, can be more useful than aerial ace in terms of strength. :x However, I'm afraid I'm going to have to disagree with the poster on hyper beam, since it generally leaves you wide open to the opponent setting up on you and basically gives them a free turn, it's really not worth it in the end. :(

On Dialga, try Dragon Pulse or Draco Meteor, both are STAB attacks and special, so it fits right into what you want. It just depends on whether you're willing to keep it in for a while or not, though. The reason why you shouldn't use Roar of Time is basically for the same reason you wouldn't use Hyper Beam, leaving you immobile for a turn, which you really don't want. Slash is generally not a great attack, so you could go with any of the various special attacks of other types, really. Just anything but a physical normal type attack.

Have fun fixing up this team either way!

I need Staraptor to use fly. It's the most useful HM and I hate walking it takes forever especially when you walk through snow/mud.