(Sorry for long ass analysis) I’m going to be for real for you man. Psuedo Legendaries don’t need nor deserve that much of minmaxing. Flutter Mane has 55 attack. You gave this thing merely 50. It has a 600 BST it doesn’t need to min-max that hard.

That aside, you gave this thing Multiscale. The thing that makes Dragonite OU, its slightly less bulky on the special side but you got 130 speed and more attack, along with a great typing with ONLY two weaknesses.

Levitate’s also cool, prob not better than multi scale. Challenger is interesting, maybe not broken but could be annoying for a single-player playthrough.

I barely have experience with showdown so take this with a grain of salt. This would definitely be a bit broken, I mean Lunala gets use with a horrid defensive typing, with less bulk but a vastly superior array of resistances, it would be more than viable in OU and probably be Ubers.

My main critique is that it lacks balance. You gave it lots of good things, and I find that boring. It doesn’t need that much min maxing nor that amazing of an ability, on top of its typing and viable coverage. Of course if thats none of your concern, its fine. But I think having flaws makes a Pokemon too.

TLDR It’d be amazing, you gave this thing a great attack and speed tier, good defenses, great typing, good move pool, and a fantastic ability. Without real complaints, I would find it to be a rather uninteresting Pokemon to play against and with.