>>58084523 (OP)
As far as narratively satisfying, nothing feels quite the same as crushing Blue in the original games. He's a punk, an asshole, and never accepts defeat. Great time clowning on him.
As far as best for difficulty... It's a bit more of a diffcult choice. Objectively speaking, it's probably Barry in diamond and pearl. He's got a legitimate team by the end there; Earthquake on Snorlax, Close Combat on Heracross, and good coverage on most his mons. He's really only held back by everything's relatively low speed.
I think there's something to be said about providing a challenge early though. Late game pokemon struggles to provide any meaningful challenge to even kids. Early in the game, when you're limited on options and still team building however, the game can throw a hell of a curveball at you and your suddenly stumped with limited options. Brock and Misty for Charmander starters, Whitney, and Wattson for Treeko starters, for example, can provide a much more of a satisfying hurdle to over come than even their repsectively elite 4s when your learning the game.
Thus, there's a case to be made for May/Brendan in Ruby Sapphire, solely for the under the bike trail fight.
I think I'll still give it to Barry, but I could see an argument for May/Brendan
