Haxorus

Haxorus is an appealing sweeper on paper; it has a serviceable Speed tier that beats Excadrill and Rotom-W, coverage in Poison Jab and Close Combat to hit checks like Primarina, Togekiss, and Celesteela, and a Double Dance strategy through Swords Dance + Scale Shot. Unfortunately, Haxorus faces multiple issues that severely limit it within UU. Scale Shot is a very unreliable STAB move that can fall flat on damage and lacks the power to threaten common defensive staples such as Amoonguss and Hippowdon. Defense drops from Scale Shot and Close Combat make Haxorus much easier to revenge kill with priority such as Bullet Punch. Haxorus also finds itself reliant on Life Orb to do necessary amounts of damage, which only worsens its longevity issues stemming from its lack of bulk, resistances, and safe setup opportunities. It can therefore struggle to enact Double Dance and finds itself pressured a lot by faster threats like Nihilego and Hydreigon. It's typically outclassed on its theoretical hyper offense teams by other setup sweepers like Salamence and Gyarados, which have better bulk, types, and moves.