>>46497270The "story" mode where you unlock all tournaments until finally doing the stargazer colossuem is easy, i'd recommend using NFEs, strong unevolved mons or weak final form mons and middle stages. Pokemon like carnivine, gabite ponyta etc, if you go for this power level you'll have fun.
After you finish the "main" part of the game, you gain acces to the cool part of the stargazer colosseum, where you have double battles against strong enemy teams with decent AIs, that will get harder and more interesting until you reach the 8th set. This is the cool part of the game, and it is 100 times better than the "main story" of PBR. You have to do the stargazer colosseum 8 times, each will a be different set of battles, until you reach tthe final set 8.
For the postgame of PBR you only have a chance if you have a trained fully-evolved team, with some minimal synergy and strategy. I personally find the postgame from stargazer colosseum harder and more fun than any battle facility in the official games. The opposing teams are not randomly generated, they have premade sets and strategies that can easily destroy casual players. If you beat it without using ubers i consider you have beaten the hardest challenge you can get from official pokemon.