OU RMT

Scizor (M) @ Choice Band
Trait: Technician
EVs: 252 Atk / 252 HP / 4 SDef
Adamant Nature
- Superpower
- Bullet Punch
- Pursuit
- Bug Bite

Blissey (F) @ Leftovers
Trait: Natural Cure
EVs: 252 HP / 252 SDef / 4 Spd
Careful Nature
- Aromatherapy
- Softboiled
- Thunder Wave
- Seismic Toss

Dragonite @ Leftovers
Trait: Multiscale
EVs: 252 Atk / 252 Spd / 4 SDef
Adamant Nature
IVs: 30 Atk / 30 Def
- Roost
- Dragon Claw
- Dragon Dance
- ExtremeSpeed

Infernape @ Choice Scarf
Trait: Iron Fist
EVs: 252 Spd / 252 Atk / 4 SDef
Jolly Nature
- U-turn
- Close Combat
- ThunderPunch
- Fire Punch

Ferrothorn @ Leftovers
Trait: Iron Barbs
EVs: 100 Def / 252 HP / 156 SDef
Impish Nature
- Stealth Rock
- Thunder Wave
- Leech Seed
- Power Whip

Starmie @ Life Orb
Trait: Natural Cure
EVs: 252 SAtk / 252 Spd / 4 HP
Timid Nature
- Psyshock
- Hydro Pump
- Ice Beam
- Thunderbolt

Should i switch out my dragonite for a garchomp?

Choice Scizor is better with U-turn so that it can scout the opponent. Its EV spread should also be 248 HP/252 Atk/8 Spe to let it take less damage from hazards when it switches in as maxing out HP leaves its HP divisible by 8, which means that it gets KOed if it switches in to Stealth Rock 8 times (assuming it never got hit during those switch-ins).

Blissey's EV spread should be Calm with 4 HP/252 Def/252 SDef to let it take physical hits better.

Fire Punch is important on DD Dragonite, as this lets it hit Steels Pokémon outside of Heatran (who's immune to Fire thanks to its Flash Fire ability). You should give up ExtremeSpeed or Roost for it.

Flare Blitz >>>>>>>>>>>>>>>>> Fire Punch on Infernape, even if you have Iron Fist as your ability, as an Iron Fist-boosted Fire Punch is still weaker than Flare Blitz. Also, Close Combat doesn't benefit from Iron Fist, despite the animation. Iron Fist is still useful for powering up ThunderPunch, though.

Fit in Rapid Spin on Starmie somewhere (like, say, over Psyshock), as Dragonite really hates having Stealth Rock on the field.