Blaze Black 2 revived my love for Pokémon, PLAY HACKROMS. It's what Pokémon was like in our imaginations. Not even just this one, any good hackrom will probably offer a challenge.
>Raid boss Vespiqueen, 3 mons to take her down
>Rest of the team evenly matched using status moves left and right.
>Cyndaquil using his SOUL to beat Leavany and take that badge
>.. and take that badge
>Wait why is the music changing?
>BURGH STILL HAD A FUCKING SCYTHER WITH QUICK ATTACK
I had to try 5 more times until I won. And Burgh changed his mon order depending on the battle, I once managed to successfully cheese Vespiqueen without losses so he sent Leavnny second and swept my whole unprepared team. In the end I had to cheese Scyther with Arbok + Growlithe intimidation combo and even then they died because Scyther uses crit moves. Gym battles actually feel like the bosses they're supposed to be lore-wise, levels are just cosmetic. I can buy that they're all strong in-universe and a big deal, not something any kid can beat. Having all 8 badges and making it to the League is supposed to be legendary and something usually reserved for professional adults.

This really fulfills my immersion, the trainer fantasy. Overleveling is for bitches if I might add, these are meant to be faced being a bit underleveled or equal at most with some grinding.
But with the strategies Gym leaders have, even being a few levels above won't sweep them, you still gotta use tactics.

Also great part of why is this even possible to begin with, is that the hackrom buffed ALL Pokémon into being usable. Stat, type changes for some, and movepools. You catch Rattatas with flame wheel and sucker punch for example.
You can strategize with your entire BOX and so do the Gym Leaders (lvl 25 Vespiqueen was barely harmed by my lvl 27 Cyndaquil) so it's stupidly fun.