Nidoking

Nidoking's amazing offensive typing combined with its ability Sheer Force turns it into a very powerful wallbreaker in the UnderUsed tier. Between its STAB moves and Ice Beam, Nidoking is able to hit the majority of the tier super effectively, meaning it has a very flexible last moveslot for another option such as Substitute or Taunt. By virtue of its typing, Nidoking is able to check Pokemon like Tentacruel and Primarina offensively and switch into Pokemon like Klefki and Zeraora with ease. Furthermore, Nidoking sets itself apart from its counterpart, Nidoqueen, thanks to its better Speed tier and better overall offensive capabilities. However, its average Speed tier makes it slower than Pokemon like Latias, Hydreigon, and Krookodile, meaning it can be easily revenge killed. It's also held back by its weakness to common typings in Ground, Psychic, Water, and Ice, making it easily exploitable by Pokemon like Krookodile, Latias, Starmie, and Kyurem. Nidoking's mediocre bulk also makes it hard for it to find opportunities to switch in.