Ferrothorn

There is no Pokemon in BW OU with the same effectiveness as a supporter as Ferrothorn. With a great defensive typing, good stats, and a fantastic support movepool that includes Spikes, Stealth Rock, and Knock Off, it is an invaluable addition to offensive and defensive teams alike. The ability to absorb powerful hits from and check Dragon-type attackers like Latios, Kyurem-B, Dragonite, and Salamence gives Ferrothorn many opportunities to switch in, as does its ability to take powerful Water-type attacks like Hydro Pump from Choice Specs Keldeo and Starmie. Once in, it can set entry hazards, remove the foe's item, or use either of its two powerful STAB moves. However, it must always watch out for a Scald burn from bulky Water-types and Will-O-Wisp from Rotom-W and Jellicent, since being burned greatly reduces its utility. Burn is so fundamental in breaking Ferrothorn that most rain teams spam Scald versus it just to fish for the 30% burn chance. Ferrothorn must also watch out for Trick Latios, since being Choice-locked basically removes it from the game. Its other drawbacks are its Fighting weakness, 4x Fire weakness, and lack of reliable recovery.