Clefable

Blessed with the ability Magic Guard, Clefable is a serviceable support Pokemon in BW OU with an immunity to the widespread residual damage sources in the tier. In a metagame defined by permanent sand and rain-boosted Scald, Clefable differentiates itself from other special walls through its passive longevity and—most importantly in a tier with Spikes Skarmory and Ferrothorn—little reliance on Rapid Spin support. Utilizing these traits, Clefable easily finds entry points on many passive Pokemon and disrupts opposing teams with tools such as Knock Off and Thunder Wave.

That said, Clefable's lack of resistances and middling stat spread is exploitable in a generation also renowned for offensive power creep. Compared with other dedicated special walls such as Blissey, Clefable's bulk doesn't hold up in the face of more powerful wallbreakers such as Thundurus-T, Choice Specs Latios, and boosted Volcarona. A reliance on Thunder Wave to drive progress also makes Clefable exploitable by the wide range of offensive Ground-types in BW OU. A sole weakness to Fighting, similarly, is a limitation for Clefable considering the introduction of Keldeo and Terrakion as well as the widespread use of Focus Blast and Superpower as coverage.