Regirock

Competitively, Regirock is often compared to Registeel, who boasts more balanced defensive stats and a superior set of resistances. However, Regirock fits a specific niche in countering the Fire-types running rampant in the UU metagame. Regirock has a superior Attack stat and STAB typing as well, allowing it to deal with Moltres and other Pokemon whom Registeel has trouble with.

Because of its ability to reliably set up Stealth Rock, counter many top threats in the metagame, and use Explosion when it's finished, Regirock is one of the best tanks in UU. Unlike many other walls in UU, it can take hits from a wide variety of UU Pokemon while also dishing damage back out, and is easily a top contender in the UU metagame.