Darn, just as i was gonna pull one of my own. Ok so, in order to not be given the Red Card, Let's talk about Lugia.
Imo, Lugia doesn't seem so oppressive for the meta, I mean obviously it isnt an offensive juggernaut like Zamazenta or Darkrai. What it does have is massive bulk, putting the likes of Toxapex to shame. However, its typing is far worse of defensively than Toxapex, it isnt bad, but imo its going to be competing with the likes of Skeledirge and Garganacl as a Tera Hog. Psychic/Flying matches up pretty poorly into a ton of meta mons, most notable among these are the Pursuitters, Mega Tyranitar and Weavile, which not only it fears Pursuit, it also fears their secondary STAB. Even outside of pursuitters its typing has problems, mons like Raging Bolt, Zapdos, Tapu Koko, Mega Diancie, Iron Boulder, Kyurem, Ceruledge, hell, even Fucking Mega Banette (looking at you
about15guys) can all hit for supereffective STAB. It is also very vulnerable to status, mainly Toxic, so defensive teams have a way to beat it easily unless its pairs with a mon that absorb the status(aka Gliscor) or run either Tera Steel or Poison. So it might even feel like a liability from what im saying, do obciously we can't tell how big its impact would be until its here.
Now, what are it's potential sets?
I feel like it would be 2 sets, a defensive set, and a Calm Mind set. The defensive would focus on Lugia taking a big blow from a sweeper and phazing it our with Roar. It can also throw out Future Sights quite effectively, and if you seen Galar Slowking or Tapu Lele, you should know how dangerous that move can be. Recover or Roost for a recovery options, with Roost even removing its Flying weakness for a turn. The other set would be the Calm Minder, which i feel like it would be the more popular of the two sets. Aeroblast is seems like a good choice, 100 base power with a high crit ratio, do with 95% acc. Air Slash is also on the table, 25 less base power, similar accuracy, but with a 30% flich rate. Earth Power seems like a good covergae options, mainly against Rock and Electric types. Psychic Noise would be a good way to interrupt more defensive teams, and Substitute would let it play around status.
So, where would Lugia fit in?
I think that most likely on balanced teams that are looking for a raw hittaker. Its bulk is obviously pretty good, and it could take a hit incoming hit from a potential sweeper like Gouging Fire or Iron Crown for example, adding the fact it has Multiscale as one of its abilities, and it can very likely shrug of big hits, making the defensive set a potential candidate for these teams, even do it would have competition with the all mighty Galar Slowking. One potential partner for Lugia would be Zamazenta (who wouldve taught, two box art legendaries pairing well together, oh boy) Zamazenta would help Lugia greatly with Lugia's Pursuit weakness, and Lugia could handle Phychic types like Tapu Lele for it. Another Solid team option would be Gliscor, not only is Gliscor a good status absorber, its also a good Knock off absorber, allowing to protect Lugia's Lefties or Boots quite nicely. Clefable is another mon for this role, with Magic Guard completly blanking passive damage. Garganacl could be used as well, not only for its full on immunity to status, but also for its Ghost resistance due to its Purifying Salt ability, and Lugia could also return it the favor by having a Ground immunity. altough they would both be competing for the Tera slot. Stall teams could use it, but they prefer having mons not just with good bulk, but also mons with typings that matchup well vs the rest of the metagame. And again, Lugia's typing is middling, even do it matches up quitr greatly into Tapu Lele, which stall teams can often struggle with, Corviknight does a similar function already, with Pressure and everything to boot, altough Lugia has more bulk. So in a way, Lugia would play a mix of Corvinkight with Toxapex, where it uses it huge bulk to withstand something and then phaze it.(sadly it doesn't learn Haze)
So overall, I think Lugia would fit in just fine. Its has some good pros but also some bad cons. Its typing seems to be letting it down more times than not, and its seems like it would need Tera to accomplish much. It does have solid bulk, of which even with the bad typing, it can survive big hits. Much like Mega Tyranitar, it has such a high bulk, that even supereffective hits dont seem to do much to it. I would be
in favor of a suspect test, and if it ends up being too much, then simply leave it banned, just like how we did with Roaring Moon a while back, simple.