Starmie
Nature: Timid
Item: Leftovers
EVs: EVs: 160 HP / 56 Def / 148 Spd / 144 SAtk
-Ice Beam/Rapid Spin
-Recover
-Surf
-Thunderbolt
Don't use a Rain Dancing Starmie. It looks good on paper, but against competitive players, it won't work too great. The general rule is: don't use Rain Dance unless your Pokemon has a Swift Swim trait. Besides, you have two Pokemon on your team that get messed up by the rain so Rain Dance is really harmful.
Also, Psychic shouldn't be used on Starmie. I know this sounds weird, but trust me, Starmie's other attacks handle all the Pokemon its able to defeat.
If this is for Netbattle, then you'll want Rapid Spin. True, half of your team is immune to Spikes, but it'll hurt your other half.
Finally, check to see if your Starmie has the Natural Cure trait. If it has Illuminate, don't use that.
Charizard
Nature: Adamant
Item: Salac Berry
EVs: 204 Atk / 252 Spd / 52 SAtk
-Aeriel Ace
-Swords Dance
-Flamethrower
-Earthquake
I've never seen a Dragon Dancing Charizard before. It works, but if you want a Dragon Dancer, use Salamence or Dragonite, not Charizard (or use your Rayquaza instead). Charizard, unlike those other dragons, has the benefit of learning Swords Dance, which powers up its attack way faster.
You could also use Belly Drum Zard, which is risky, but very awesome if you can pull it off:
Charizard (M) @ Salac Berry
Trait: Blaze
EVs: 12 HP / 252 Atk / 116 Spd / 130 SAtk
Adamant Nature (+Atk, -SAtk)
- Substitute/Overheat
- Hidden Power [Flying]
- Earthquake/Rock Slide
- Belly Drum
Make sure the Pokemon you're up against isn't faster than you. Sub first, then Belly Drum, and you'll have exactly 25% HP left to activate Salac. Then you can sweep. There will always be a Pokemon you can't handle depending on the attacks you choose.
If you're a brave soul, you can replace Sub with Overheat to handle more types, but that's even harder to pull off.
Ninjask
Nature: Adamant
Item: Liechi Berry
EVs: 96 HP / 252 Atk / 160 Spd
-Hidden Power [Bug]
-Baton Pass
-Substitute
-Sword Dance
Ninjask already has Speed Boost, so why do you ever need Agility? Also, Double Team is looked down upon because only unskilled players rely on evasion. Please don't use it.
Anyways, Ninjask needs Substitute to protect itself from attacks while it sets up. It also needs an actual attack for when it can't Baton Pass any more if all your physical attackers get fainted.
Ninjask only needs 396 Speed to outrun Jolteon and Aerodactyl. So make it Adamant and give it a Liechi Berry. Giving Ninjask excessive speed is pointless.
Bellossom
Nature: Modest
Item: Leftovers
EVs: 8 HP / 248 Spd / 252 SAtk
-Hidden Power [Fire]
-Sleep Powder
-Sunny Day
-Solarbeam
The moveset is fine. The EVs seriously need work. Why are you putting Attack EVs into something that doesn't have any physical attacks?
Max out its Sp. Attack to hit as hard as possible and give it a total of 198 Spd so that it can outrun base 130 speeders (Jolteon and Aerodactyl which I mentioned above, also Crobat).
Aggron
Nature: Adament
Item: Choice Band
EVs: 163 Atk/248 Def/5 Sp Atk/207 Sp Def/230 Spd
-Rock Slide
-Iron Tail
-Earthquake
-Double-Edge
Aggron isn't good in OU since its weak against so many common types (Water, Fighting, Ground). If you want to use this set, at least give it Choice Band. But you should replace it anyways so I won't bother with the EVs.
Rayquaza
Nature: Adamant
EVs: 104 HP / 252 Atk / 152 Spd
-Hidden Power [Flying]
-Dragon Dance
-Rock Slide
-Earthquake
Uh, it's Rayquaza. Well, this is your chance to use a Dragon Dancer.
