Ok, time for some extreme sweeping to round this off:
Salamence @ Life Orb
Trait: Moxie
Jolly nature, 4 HP / 252 Atk / 252 Spe
Dragon Dance / Outrage / Earthquake / Roost
Here's where it gets fun. Salamence's humongous power even without boosts means that it will always get at least one kill a match- unless Ginga's team puts in a Salamence counter next, but I'll get to that later. The awesome thing is, Thundurus and Kyurem are all OHKO'd, while Metagross, Terrakion, and Meloetta (Terrakion and Meloetta are OHKO'd with SR) is 2HKO'd.
That's at +0. At +1, everything is OHKO'd by either Outrage or Earthquake with SR, and everything is outsped as well. With Roost, it keeps its longetivity, though if need be we can replace it for Fire Blast, and tweak its spread a bit. This means that with a Moxie boost, things will die quickly.
Some UNBOOSTED calcs:
252 Atk Outrage to 0/0 Meloetta: 95-113%
252 Atk Outrage to 0/4 Thundurus-T: 117-138%
252 Atk Outrage to 56/0 Kyurem: 142-167%
252 Atk EQ to 0/0 Terrakion: 98-116%
252 Atk EQ to 252/4 Metagross: 64-75%
As you can see, with SR up and at +1, Salamence OHKO's everybody with either EQ or Outrage. Heck, at +1, Outrage flat out OHKO's everyone bar Metagross, who is 2HKO'd with Rocks up. So just spam Outrage.
How Ginga's team could react:
Skarmory- weak to Rotom, and Heatran. If they do that, it'll be in our favor, not theirs.
Bronzong- same as above, Celebi can take this one on as well.
Gliscor- Celebi, Rotom, Mamoswine, and Heatran, kind of. Easy set up fodder.
Steels- Heatran, Rotom, Mamoswine, even Scizor can handle these guys. Not a problem at all.
Physically defensive pokemon- Most are easy pickings for Celebi, Rotom, and Heatran. Depending on their type, Scizor/Mamoswine can handle some as well.
Now, you may say, well, can Salamence set up?
Heck yes. Well, kind of. But yes, the answer is yes. Meloetta fails to KO with Psychic, which will allow you to get to +1 and KO back.
The general rule is, keep SR on your opponent's side, try to come in without having to take a hit, and avoid Terrakion, and Kyurem behind a Sub. Let Scizor handle those. Only confront Thundurus-T if you're at +1. That's basically it; Meloetta can be set up upon most of the time as well(barring paralysis from Thunder).
Lum Berry can be used, but you lose the ability to OHKO Thundurus-T with Outrage, and the ability to OHKO Meloetta with SR up. Still, you can still nail Kyurem, but your chances of getting that Moxie boost are lower.