Skarmory

Skarmory is a defensive staple in BW OU, checking many of its best Pokemon and avoiding passivity by setting up entry hazards. It's able to check Ground-types like Excadrill, Mamoswine, Garchomp, and Landorus-T as well as other common Pokemon like Scizor, Breloom, Tyranitar lacking Fire Blast, and Dragonite lacking Fire Punch. Roost and immunity to common residual damage methods like Spikes, sand, and Toxic let it consistently handle them. Normally physically defensive, it can also run a specially defensive EV spread to switch into Pokemon like Alakazam, Latios, and Tornadus while still checking most of the aforementioned threats relatively well. This gives it flexibility in fitting on teams. Setting Spikes, besides reducing its passivity, achieves fantastic progress for teams. Its defensive utility and ability to counter Excadrill, one of the most common spinners, and punish it with Rocky Helmet lets it keep entry hazards up more consistently. These traits alongside Stealth Rock and Sturdy also make it a great Custap Berry lead on hyper offense teams. Spikes also wears down Skarmory's common switch-ins, like Heatran, Jellicent, and Politoed, especially with Whirlwind. However, Skarmory's Fire and Electric weaknesses let common Pokemon, like Heatran and Thundurus-T, and specialized coverage, like Fire Blast on Tyranitar and Garchomp, get past it. Strong special attackers like Keldeo, Alakazam, and Latios can overwhelm physically defensive sets, as can common rain threats, with Tentacruel and Starmie successfully spinning on burned Skarmory. Magnezone, often paired with the Dragon-types Skarmory checks like Garchomp and Dragonite lacking Fire Punch, can trap and remove Skarmory. Skarmory also cannot punish Pokemon immune to Spikes, like Reuniclus, Rotom-W, and Xatu, which can hit it super effectively, set up on it, punish Spikes and Whirlwind with Magic Bounce, or inflict it with status. Ferrothorn competes with it on sand teams as a Steel-types Spikes setter, resisting Water and having better special bulk to stave off rain teams. Skarmory also competes with other Steel-types like Heatran and Jirachi given their better offensive presence and prowess in checking Psychic-types, respectively.