Poliwrath

Poliwrath has always been at the lower end of Water-types in the lower tiers, but it does have several defensive advantages over many of them. For starters, it has a unique defensive typing in Water / Fighting as well as Water Absorb, giving it a great immunity to Water and resistances to powerful types such as Dark, Ice, Rock, Steel, and Bug. When paired with its good defensive stats, this allows Poliwrath to be one of the few hard counters to both Feraligatr and Suicune, and a great check to Mega Sharpedo, Krookodile, and Cobalion. It also boasts a great support movepool with moves such as Scald, Circle Throw, Haze, and Encore.

However, Poliwrath has to compete with a large number of other Water-types such as Suicune and Swampert, which both have higher defensive stats and can phaze their foes like Poliwrath can. Poliwrath also boasts very little offensive presence, which, in tandem with its lack of a good Fighting-type STAB move, means that it won't be playing any offensive roles. Defensively, it boasts no reliable recovery outside of Rest, and its typing leaves it with crippling weaknesses to Psychic, Flying, Electric, and Grass, which are all good offensive types and can be hard for its teammates to cover.