Pikachu should be the only Kanto Pokemon to get redemption from what Trip said about Kanto. Ash never told him about his other Pokemon, so Trip only saw his Pikachu(who's energy was drained) and made an assumption. Oshawott is next. It definelty needs to prove itself towards Trip as well, since it was there when Trip decided that it wasn't the Pokemon for him. Maybe an evolution might also change his mind. As far as Charizard is concerned, having it sweeping his team in the league will be bad writing just like Iris's Dragonite was doing in this Junior cup, so no. All of those Pokemon he caught shouldn't go to waist.