Aron

Aron is a unique Pokemon with a high Defense stat and nine resistances that enable it to wall Fairy- and Flying-type Pokemon such as Spritzee and Fletchling. Aron has access to the most powerful Rock-type move, Head Smash, and the ability Rock Head, which negates Head Smash's recoil. Aron also has access to Metal Burst, which can be used alongside Sturdy and its low Speed stat to severely dent foes caught off guard. However, Aron has two unfortunate 4x weaknesses to Ground and Fighting, which allow Pokemon of these types, such as Drilbur and Mienfoo respectively, to easily take advantage of it. Aron also has a 2x weakness to Water-type moves; these weaknesses, alongside Aron's low Special Defense, make it tough for Aron to fit into a metagame where these types are common. Aron's capability as a wall is also hampered by the fact that it has no recovery outside of the unreliable RestTalk, which it cannot afford to run. The only hope it has at recovery is Berry Juice, which can only be used once.