The red pokemon you get for beating the league with no faints
Shadow mewtwo
UFI
Cressilia, lemme explain. cressilia has a 1/15 chance of randomly spawning in areas around selene city and this rate cannot be changed, meaning with charm chances of you getting a shiny cres is a 1 in 1365x15 ie 1/20475.
I’d say the roaming legends, completing the dex is imo not that hard and the championship can be cheesed
for the roaming legends you can’t have charm bc once they get registered they no longer appear, they aren’t a guaranteed spawn rate, and they aren’t very popular shinies imo
your best bet might even be to pokepon them
in fact, once I get through shadow mewtwo and this dreaded victini, I plan on pokeponning my raikou
I was about to say that as well. Sure, the pokken mons or UFI are hard to get, but you can simply SR them for a shiny, on the other hand, you can’t simply SR for roaming legends, you have to encounter them over and over again until you get a shiny, which, based on the chances is a rarer occurence.
Actually getting shiny P. Machamp and P. Lucario is the hardest I would think, as you have a 1/16777216 chance of getting both shiny. Shiny Charm doesn’t affect them either. You can shiny charm the wanderers, and they’re not even close even without shiny charm.