Swampert

Mega Swampert is one of the premier physical threats in the tier and a perfect addition to rain teams, boasting an incredible Attack stat to wield its lethal STAB combination of rain-boosted Waterfall and Earthquake with. Handling Mega Swampert defensively is a nightmare, with many believing the most brutal part of Mega Swampert is the secondary effects; Waterfall's flinch chance, coupling with critical hits and Ice Punch's freeze chance, means that answers like Skarmory and Mega Latias can regularly be overcome given how many attempts Mega Swampert has to break them during a game. It's no slouch when it comes to defensive utility, either; its impressive bulk and wonderful typing allow it to switch in and trade blows against many Pokemon like Assault Vest Magearna and Tapu Koko. It can also overcome traditional answers to itself with Toxic and remove the chance for foes to switch around its attacks with Substitute. The most fatal blow to Swampert's viability is Rotom-W, a very common Pokemon that happens to handle both of its STAB moves and Ice Punch while threatening it back with Will-O-Wisp and rain-boosted Hydro Pump. Swampert's 4x weakness to Grass can be exploited by the likes of Kartana, Tapu Bulu, and Mega Alakazam, and it despises Toxic Spikes from Toxapex putting it on a timer.