Azumarill

With physical STAB, the equivalent of 150 base Attack, decent defenses, and convenient typing, Azumarill can run circles around unprepared teams. With a Choice Band, it can break down even UU's bulkiest walls with the appropriate move, 2HKOing Slowbro, Milotic, Regirock, Registeel, Steelix, and Spiritomb. Substitute variants can take advantage of a wide range of defensive Pokemon including Chansey and Registeel, breaking the mid-game wide open with a massive Attack stat and decent coverage. Azumarill has a niche on offensive teams due to its good defenses, ability to take hits, and STAB priority move. Although Aqua Jet somewhat alleviates Azumarill's Speed concerns, its subpar Speed is still its greatest shortcoming.