Arceus

Arceus is debatably Ubers's most terrifying and dangerous setup sweeper thanks to a powerful STAB-boosted Extreme Speed, decent defenses, and a wide array of utility and coverage moves, letting it mix and match to win problematic matchups easily. Arceus also has an excellent defensive profile, allowing it to take on Ghost-types like Lunala and Flutter Mane. Extreme Speed allows Arceus to operate as a revenge killer, making it difficult for opposing setup sweepers like Scale Shot Koraidon, Miraidon, and Rayquaza to sweep. However, Arceus is not without its flaws, as physically bulky walls like Ting-Lu, Arceus-Water, and especially Necrozma-DM all check it and give it difficulty when attempting to sweep. Furthermore, while more uncommon, Arceus often struggles to beat bulky Ghost-types like Tera Ghost Koraidon, Tera Ghost Miraidon, Giratina-O, Lunala, and Skeledirge, as they can tank unboosted Shadow Claw and cripple Arceus with status. Arceus's lack of resistances and weakness to status moves like Will-O-Wisp, Toxic, and Thunder Wave can make it potentially hard to switch onto the battlefield safely. Despite that, Arceus is still one of the best Pokemon in Ubers, and every team must prep for it if they do not want to get easily cleaned by it.