Volcanion

Volcanion's unique typing and decent well-rounded stats give it a niche in the tier, with its defensive utility including forcing out Fire-types like Volcarona and Heatran and proving useful against Water-types like Ash-Greninja, Tapu Fini, and Manaphy. Its ability also provides free entry and recovery from Scald from the likes of Toxapex and Slowbro. Its signature move, Steam Eruption, is like Scald on steroids, and the burn chance often makes Volcanion quite unpleasant to switch into even for solid defensive answers. However, it doesn't have the offensive prowess to justify its low Speed, so it finds itself walled by common defensive Pokemon like Mega Latias, Toxapex, and especially Chansey. It has some incredibly frustrating weaknesses in Rock, Ground, and Electric, the first one punishing Volcanion with the omnipresent Stealth Rock and the last two being common offensive types. It also has no reliable recovery, so its defensive value comes from immediate bulk rather than longevity.