Magneton

Magneton is a great special wallbreaker that utilizes its blend of offensive and defensive capabilities to generate momentum for offensive teams. Magneton's rare Steel typing gives it a wide array of resistances that enable it to check Pokemon like Skuntank, Vileplume, Jynx, and Regirock and Cradily lacking Earthquake. Not only this, but Magneton's shockingly high base 120 Special Attack paired with an almost unresisted STAB combination means it trades well against these Pokemon while pressuring switches with ease. Since these traits are usually enough for Magneton to function, its moveslots and abilities are flexible enough to cover weaker matchups.

However, Magneton isn't completely immovable and has its share of offensive shortcomings. Magneton's low base HP means it can take a sizable chunk of damage even from offensive Pokemon with attacks it can resist, and the same can be said for defensive Pokemon with Seismic Toss like Dusclops and Lickilicky. Magneton's base 70 Speed allows it to outpace a majority of defensive Pokemon, but it's slow compared to other mid-Speed wallbreakers in the tier such as Hitmonchan, Gardevoir, and Medicham, meaning it isn't hard to offensively check.