Gen 3 RMT annoyingly OU

#1
Medicham (M) @ Lum Berry
Trait: Pure Power
EVs: 4 HP / 252 Atk / 252 Spd
Adamant Nature (+Atk, -SAtk)
- Brick Break
- Fake Out
- Rock Slide
- Shadow Ball
Magneton @ Salac Berry
Trait: Magnet Pull
EVs: 4 HP / 252 Spd / 252 SAtk
Timid Nature (+Spd, -Atk)
- Endure
- Hidden Power [Fire]
- Thunder Wave
- Thunderbolt
Zapdos @ Leftovers
Trait: Pressure
EVs: 4 HP / 252 Spd / 252 SAtk
Modest Nature (+SAtk, -Atk)
- Extrasensory
- Hidden Power [Ice]
- Metal Sound
- Thunderbolt
Weezing (M) @ Leftovers
Trait: Levitate
EVs: 252 HP / 24 Atk / 96 Def / 136 SDef
Sassy Nature (+SDef, -Spd)
- Haze
- Pain Split
- Sludge Bomb
- Will-O-Wisp
Skarmory (F) @ Leftovers
Trait: Sturdy
EVs: 252 HP / 252 Def / 4 SDef
Impish Nature (+Def, -SAtk)
- Aerial Ace
- Rest
- Spikes
- Whirlwind
Blissey (F) @ Leftovers
Trait: Natural Cure
EVs: 252 HP / 4 Def / 252 SDef
Calm Nature (+SDef, -Atk)
- Aromatherapy
- Ice Beam
- Seismic Toss
- Softboiled
 

Umby

I'm gonna bury you in the ground~
is a Contributor Alumnus
#2
Medicham (M) @ Lum Berry
Trait: Pure Power
EVs: 4 HP / 252 Atk / 252 Spd
Adamant Nature (+Atk, -SAtk)
- Brick Break
- Fake Out
- Rock Slide
- Shadow Ball

You don't have a reason not to use a Choice Band on this.

Magneton @ Salac Berry
Trait: Magnet Pull
EVs: 4 HP / 252 Spd / 252 SAtk
Timid Nature (+Spd, -Atk)
- Endure
- Hidden Power [Fire]
- Thunder Wave
- Thunderbolt

If you're going to Salac, use HP Ice or Grass to get rid of Dugtrio, which is the main reason for using endure-salac Magneton. Otherwise just use Substitute > Endure and Leftovers > Salac.

Zapdos @ Leftovers
Trait: Pressure
EVs: 4 HP / 252 Spd / 252 SAtk
Modest Nature (+SAtk, -Atk)
- Extrasensory
- Hidden Power [Ice]
- Metal Sound
- Thunderbolt

Extrasensory isn't really doing anything for you. Just use Thunder Wave or Substitute

Weezing (M) @ Leftovers
Trait: Levitate
EVs: 252 HP / 24 Atk / 96 Def / 136 SDef
Sassy Nature (+SDef, -Spd)
- Haze
- Pain Split
- Sludge Bomb
- Will-O-Wisp

Why so much SDef? Even physical tanks need a good amount of investment i their Defense.

Skarmory (F) @ Leftovers
Trait: Sturdy
EVs: 252 HP / 252 Def / 4 SDef
Impish Nature (+Def, -SAtk)
- Hidden Power [Flying]
- Rest
- Spikes
- Whirlwind

Or Drill Peck + Roar. Whichever you like more.

Blissey (F) @ Leftovers
Trait: Natural Cure
EVs: 252 HP / 4 Def / 252 SDef
Calm Nature (+SDef, -Atk)
- Aromatherapy
- Ice Beam
- Seismic Toss
- Softboiled

Rule #1 for Blissey is to always use Max Defense and a Bold Nature, or something similiar to that effect. Blissey does not need SDef EVs.
Random things thrown together are random things. DDTar (or just Tyranitar in general) destroys this team hands down. You'll also have issues hitting Swampert hard enough to prevent it from being an annoyance.