Gen 3 RMT

Salamence (M) @ Leftovers
Trait: Intimidate
EVs: 108 HP / 252 Atk / 148 Spd
Adamant Nature (+Atk, -SAtk)
- Hidden Power [Flying]
- Rock Slide
- Earthquake
- Dragon Dance

Pretty standard starter. Doesn't give me a giant advantage over anything, but I have solid switches for the common leads. 148 speed because I am a giant speed creep. Insanely important mid-game when taking Megahorns, Focus Punches, and Earthquakes. A lot of the time, when Salamence goes down early, I can't take the opposing CBTar / CBCross / etc.

Celebi @ Leftovers
Trait: Natural Cure
EVs: 252 HP / 4 Atk / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Swords Dance
- Baton Pass
- Hidden Power [Fighting]
- Recover

Passes Swords Dance to any one of my three threatening sweepers. A lot of the time I Swords Dance as they bring in Salamence, BP to my own Salamence, and either KO with Rock Slide if they're DD or Dragon Dance and sweep with a +3 +1 Salamence if they're CB. Abuses bulky waters like Swampert and Milotic to the fullest. Metagross + Celebi is a great combo; SD up on the bulky water and pass to Metagross who can now 2HKO them with Earthquake.

Magneton @ Leftovers
Trait: Magnet Pull
EVs: 112 HP / 252 SAtk / 144 Spd
Modest Nature (+SAtk, -Atk)
- Thunderbolt
- Rest
- Hidden Power [Ice]
- Sleep Talk

Fuck MoP. He says this thing is necessary in every team unless you like taking 25% per switch in, but it's totally useless. Forretress still Earthquakes this thing to hell, and it can't even OHKO max/max+ Skarmory. That is, if they even have a Skarmory. 7/10 matches this thing ends up being death fodder. Replace, please.

Metagross @ Leftovers
Trait: Clear Body
EVs: 160 HP / 252 Atk / 96 Spd
Adamant Nature (+Atk, -SAtk)
- Meteor Mash
- Earthquake
- Explosion
- Agility

Another one of my powerful sweepers. Also doubles as my main CM Jirachi check. If it gets out of hand, and Earthquake isn't 2HKOing, i can just Explode. Explosion is also great in a pinch for when I need to break open something. Packs a lot of power, with a good amount of bulk and cool resistances to boot.

Snorlax (M) @ Leftovers
Trait: Immunity
EVs: 144 HP / 68 Atk / 132 Def / 164 SDef
Adamant Nature (+Atk, -SAtk)
- Curse
- Body Slam
- Rest
- Shadow Ball

Eh, I don't like Snorlax. It's my only check to random shit like Zapdos and Regice, but without Sleep Talk it's a sitting duck. Not to mention that it's Skarmory bait, so unless I make a blind double switch to Magneton, he's taking more damage every time he comes in. Shadow Ball is to patch up that massive Gengar weakness I have.

Milotic (M) @ Leftovers
Trait: Marvel Scale
EVs: 252 HP / 224 Def / 32 SDef
Bold Nature (+Def, -Atk)
- Surf
- Ice Beam
- Recover
- Light Screen

Milotic is the standard bulky water. It patches up weaknesses to Tyranitar, Salamence, and Metagross. Light Screen makes it nearly impenetrable, as well as aiding Celebi / Metagross / Salamence in setting up. It's pretty weak though.

In general, I'm just looking for some strategic help. The team isn't that good, though. In conclusion, MoP sucks.

What's HP Ice for? By itself I can only see Magneton hitting Salamence/Flygon/Celebi/Claydol with it. Salamence isn't running into a Thunderbolt/risking a Thunder Wave for you to predict a switch in and would Earthquake before you could do anything to it. You have Milotic with Salamence as a back up for Flygon. You could hit Celebi with HP Fire (If that was your aim in the first place) while being able to OHKO Forretress (though Sleep Talk would be useless in this case) or HP Grass to still hit Claydol while hitting Swampert.

If you're looking to get physical walls out the way for sure, I say go with Fire and neglect Sleep Talk for Max Modest. You can even mess around with Jirachi with Metal Sound if you wanted to (not necessary with Metagross walking around, but it's there). If Magneton ends up being fodder, as you say, then once it's done it's job, even without Sleep Talk you could just let it take sleep if you wanted.

I'm gonna make the obvious suggestion of replacing Milotic with Swampert. If you lose celebi Tyranitar is a huge problem. Back when RSE was the main Gen Tyranitar was generally considered the biggest threat. I'm not sure you need light screen, if you keep Milotic I'd put hypnosis on it.