Perrserker

Boasting a high Attack stat, two abilities that boost its damage output even further, and access to moves like Seed Bomb and Close Combat to shred the likes of Quagsire and Ferroseed, Perrserker is a very powerful wallbreaker in PU with very few safe switch-ins. In combination with its natural immunity to Toxic and sand damage, this makes for a Pokemon adept at shredding defensive cores. However, Perrserker is very slow for an offensive Pokemon, leaving it outrun and dispatched by many offensive Pokemon such as Charizard, Gallade, Archeops, and Lycanroc. This gives it a much tougher matchup against faster, more offensive teams. Its special bulk is also very lacking, so Pokemon like Galarian Articuno and Ribombee can still heavily damage Perrserker, even though it resists their STAB moves—despite being a Steel-type, Perrserker doesn't contribute much defensive value to your team.