Houndoom
-Flamethrower
-Crunch
-(an electric or normal attack (I'll have to check what it can learn))
-Sunny Day
Houndoom can't learn any Electric attacks and Normal moves should be avoided on Pokemon who aren't Normal types. If you're using that set up, use Solarbeam.
But really, the Substitute version works just as well, and maybe even better. Houndoom doesn't have the defenses to use Sunny Day. So what you do is use Substitute to see what the opponent does. If your Sub doesn't break, attack or use Will-o-wisp on any physical attackers. That will help out Houndoom's weak defenses. Sub also protects Houndoom from all status inflictions.
Bellossom
-Petal Dance (I'll take the confusion along with the two-three turn attack)
-Solar Beam
-Moonlight
-Toxic
No, never ever use attacks that take more than one turn to finish (i.e. Petal Dance, Thrash, Outrage, Rollout, Dig, Fly, Dive, Hyper Beam, etc.). You'll seriously regret it.
Also, Bellossom is NOT Vileplume. Vileplume is an offensive Grass type, but Bellossom can't sweep as well. So don't give it Solarbeam.
Sleep Powder and Safeguard are both defensive moves that suit Bellossom's role.
Honestly, Vileplume > Bellossom.
Flygon
-Earthquake (even though in a double battle it will hurt more then help
-Dragon Claw
-Iron Tail
-Hyper Beam or Facade
It doesn't matter, a Flygon without Earthquake is a sad Flygon.
Rock Slide is better than Iron Tail. Rock Slide is supereffective against Flying types who are immune to Earthquake.
Hyper Beam sucks, and Facade won't help either. Only use Facade on Pokemon that have the Guts trait.
Now Quick Attack is a better move because it's purpose is to defeat faster opponents who are low on health. A Starmie with only 10% HP will still kill Flygon, but not if Flygon uses Quick Attack. It can be a major lifesaver.
However, Quick Attack is only an egg-move, so if you don't want to breed...use Screech for the purposes of lowering your opponent's defense.
Finally, Fire Blast > Dragon Claw. When all is said and done, the one Pokemon that will give Flygon a ton of trouble is Skarmory. But Fire Blast takes care of that.
Scizor
-Steel Wing
-Silver Wind
-Slash
-Aerial Ace or Hyper Beam
Okay, it looks like you've never used Baton Pass before.
Scizor is an okay sweeper, but its moves are kind of weak so it really needs Swords Dance in order to do any major damage.
And while Swords Dance boosts your attack, wouldn't it be nice for Flygon to have an attack boost too? The only problem is, Flygon can't learn Swords Dance but that's okay. If Scizor Baton Passes to Flygon, Flygon gets the attack boost transferred over to it! Flygon and Scizor make a nice pairing too, since Flygon resists Fire and Scizor resists Ice.
While you're at it, you might as well use Agility. This will help out if the opponent uses a Fire type. You'll be faster with Agility, so you can Baton Pass before the opponent attacks and you can pass, once again, to Flygon who really likes the speed boost.
Gardevoir
-Psychic
-Calm Mind
-Reflect
-Thunderbolt
It's fine.
Milotic
-Hydro Pump
-Ice Beam
-Recover
-Iron Tail
Surf > Hydro Pump. It's self-explanatory.
Iron Tail is useless. Milotic shouldn't use physical attacks at all.
Use Hypnosis or Toxic please.
Alternately, you can use the Rest + Sleep Talk Milotic, which I'm glad ludicolo kid explained, because I won't have to type it up now.
Now what I don't get is some of the moves you (aragornbird) suggessed. To me they seemed almost choosen at random and that goes for the moves suggessed in the moves sets sticky. Can someone explain this to me?
That's funny. To me, some of the moves you chose seem to be random. I guess it's because you're still inexperienced, so you don't know the purpose of certain moves.