Politoed

Politoed is one of the most prominent Pokemon in BW OU for one reason: its ability to put permanent rain on the field. This alone makes it one of the best support Pokemon in the metagame, as it brings out the full potential of Pokemon such as Keldeo, Tentacruel, Tornadus, and Thundurus-T. In addition, Politoed is capable of spreading status around the opposing team, allowing you to wear it down far more easily. Politoed's main shortcoming is its middling stats, as it is not capable of dishing out or soaking up significant amounts of damage. Its mediocre defensive stats are exacerbated by its vulnerability to all types of entry hazards and lack of reliable recovery.