You're halfway through, at least in Johto. Of course, the strongest ones are to come, but then again you must have some very highly trained Pokemon by now. In fact, I think my hardest battle was with Falkner, simply since my Pokemon weren't nearly as strong back then!

[She'd still had Berserker, though, and even as a Rhyhorn he'd been a force to be reckoned with, especially against fliers.]