The Elite Four (Sidney, Phoebe, Glacia, Drake) are a gauntlet of powerful trainers. You cannot heal at a Pokémon Center between battles, so bring plenty of healing items. Sidney (Dark) is weak to Fighting/Bug. Phoebe (Ghost) is weak to Ghost/Dark. Glacia (Ice) is weak to Fire/Fighting/Rock/Electric. Drake (Dragon) is weak to Ice/Dragon. A diverse team with good coverage is essential.
