What is the fastest way to defeat the elite four?

To quickly defeat the Elite Four, focus on building a well-rounded team with diverse types and strong coverage moves. Level up your Pokémon to at least 10-15 levels higher than the Elite Four members' highest level Pokémon. Utilize type advantages strategically, and carry items like healing potions and revives to maintain your team's health during battles. Finally, consider using strong stat-boosting moves and status effects to gain an edge in combat.