Hello, Karen of the Kanto-Johto Elite Four here. It took Lorelei heading to Hoenn and old lady Agatha finally croaking for me to reach the Elite Four, but here I am with an important reminder:

Strong Pokémon. Weak Pokémon. That is only the selfish perception of people. Truly skilled Trainers should try to win with the Pokémon they love best. Understand what's important.