Azumarill

Fairy

A fantastic Attack stat thanks to Huge Power, great set up potential with Belly Drum + Normalium Z, and priority in Aqua Jet allow Azumarill to pose a massive threat to balance and offense teams alike. Alternatively, Azumarill can run a Sitrus Berry on a Belly Drum set to free up a Z-Move slot for another team member. It also forces the opponent to guess which Pokemon the potential Z-Move user is. Azumarill also has use outside of its sweeping capabilities, being able to provide utility with Knock Off to cripple Pokemon like Chansey and revenge kill threats such as Nihilego with Aqua Jet. Azumarill's Speed stat can be maximized with a Jolly nature to flip the Poison matchup, letting it outpace a massive roadblock in Mega Venusaur and bypass other would-be checks such as Rotom-W and Mantine. However, a poor Speed stat, even with a Jolly nature, leaves it reliant on Aqua Jet to remove faster threats, which will not always work against common offensive Pokemon like Latios and Tapu Bulu. Azumarill has issues sweeping no matter the nature it uses: Adamant Azumarill struggles greatly with breaking through defensive cores found on types such as Flying and Electric due to its inability to outpace and remove walls such as Mantine, while Jolly Azumarill fails to OHKO prevalent walls such as Celesteela.

Water

Azumarill is unique in having an immunity to Grass-type moves thanks to its ability Sap Sipper, giving it a special niche for Water teams. Its Fairy typing brings the much-appreciated immunity to Dragon as well as a very welcome resistance to Dark, enabling it to check Pokemon like Hydreigon with ease when combined with its acceptable bulk. Azumarill's access to both Perish Song and Whirlpool allows it to act as a Perish trapper, trapping and removing many of the walls that Water hates to deal with such as Chansey, Toxapex, and Ferrothorn. As a result, Azumarill fits on both balance and stall teams to serve as a great stallbreaker and tank. It is a huge drain on momentum, though, meaning even if offense teams need its support to beat certain walls such as Mega Venusaur, it's too much of a liability to use. Its only form of recovery is Rest, which is unreliable when trying to trap Pokemon that aren't walls and only makes its momentum problems even worse. Azumarill is also very one dimensional and uses a predictable strategy, so it may be difficult to precisely trap the Pokemon you intend to. Unfortunately, while often quite useful, the Fairy typing also makes Azumarill weak to Poison, which is a matchup Water tends to be weak in, compounding a common team problem.