Yanmega

Although the transition to BW2 hasn't brought anything new for Yanmega, it is still considered a very potent special sweeper. This fact is supported by its two abilities: Tinted Lens eliminates the opponent's resistances to Yanmega's moves, making its attacks even more powerful than they already were and lowering the effectiveness of its primary checks, whereas Speed Boost increases Yanmega's Speed to sky-high levels, causing Yanmega to outspeed every Pokemon in the tier after two boosts. Moreover, Yanmega's Bug- and Flying-type STAB moves are only resisted by Zapdos, Empoleon, Rotom-H, and Registeel, and its typing lets it get relatively safe switch-ins on a lot of attacks, mainly Grass-, Ground-, Bug- , and Fighting-type moves. This makes it excellent at capitalizing on Heracross, the number one Pokemon in UU, locking itself into the wrong move.

However, every Pokemon has its flaws: Yanmega has a terrible quadruple weakness to Stealth Rock that limits its longevity throughout the battle unless you pack a Rapid Spin user on your team. It also has a relatively shallow movepool and is very frail on the special side, going down to any strong special move. Overall, even though one might say Yanmega is outclassed by Sharpedo, it is a very threatening Pokemon that can rip teams apart if not prepared for.