Damn, I was on the Japanese Global Link last night and saw this competition in the news but the way it was worded seemed like it had already been played, or even if it hadn't been then it would be Japan only (would have made the thread then). If that were the case we could have looked through Japanese blogs to see what they thought was good and CP it into our teams haha. Now we're just gonna have to play against them and see their wacky strategies first-hand!
Psynergy is right though, screens are a huge part of Rotations! Field effects in general are way better here than they are in regular Singles, so you can make use of stuff like Trick Room, Tailwind, Safeguard, and manual weather much better. Screens are so big that Brick Break is actually a common move on stuff like Garchomp, lol. Set up sweepers are massive as well, since unlike in Singles where switching wastes your boosts, you can just rotate and retain them. Switching in general pretty much never happens, so Stealth Rock is worthless, and weird things like Yawn, stat de-buffs etc. (basically anything that you'd want to switch out of in Singles) are really annoying.
PS! may not have a ladder to play on due to no rotations, but remember that you can play free-battles on Battle Spot where legendaries are allowed to practice. I can guarantee that the place will be full of teams for this comp in the lead up (but of course feature some random ones from little kids. It's not perfect, lol). We might even need to have a pre-comp practice tourney on IRC!
I don't have access to RNGs of my own so I'm limited to my own gen VI soft resets and anything I can trade for, but brb I'm off to find a Multiscale Lugia for screens setting
edit: the lag in this comp will be extreme. triples / rotations is already pretty laggy from all the Pokemon on the field, but the big legendary models don't help that at all. Wonder if that will affect the battle timer at all with stally strategies