Gengar

Gengar is a potent threat in DPP OU due to its unique mix of utility and offensive firepower. Gengar's typing, Speed, and ability make it an offensive spinblocker and allows it to check several threats through its immunities to Normal-, Fighting-, and Ground-type attacks, such as Breloom, Lucario, and Gliscor. Unlike the other prominent Ghost-type, Rotom-A, Gengar has Focus Blast to OHKO bulkless Tyranitar and 2HKO Clefable. Focus Blast also provides Gengar perfect coverage in two moves alongside Shadow Ball, giving it many opportunities to take advantage of its large movepool to diversify its options. With Will-O-Wisp and Taunt, Gengar shuts down defensive counterplay from Hippowdon, Blissey, and Clefable while spreading burns to Bronzong, Jirachi, and Skarmory. Substitute sets can take advantage of the switches it forces to either heal itself with Pain Split or power through checks such as Scizor and Choice Scarf Tyranitar. Gengar's access to Explosion and coverage options such as Thunderbolt make it a powerful force, as it hits Pokemon such as Latias, Blissey, and Gyarados very hard.

Gengar's primary flaws lie in its weakness to Dark-types, frailty, and prominent low accuracy moves. Tyranitar is the bane of Gengar's existence, as despite being able to OHKO it with Focus Blast and burn it with Will-O-Wisp, Choice Scarf Tyranitar outspeeds Gengar and traps it with Pursuit, removing it from the game with certainty after two rounds of Stealth Rock damage. Scizor fares similarly; although it fears the rare Hidden Power Fire and doesn't appreciate being burned, it checkmates Gengar with Bullet Punch and Pursuit. While Gengar is very strong, it doesn't OHKO everything, is frail, and despises status—faster Choice Scarf Pokemon such as Flygon, Magnezone, Rotom-A, and Latias can outspeed and OHKO it, while bulkier threats such as Swampert, Dragonite, Zapdos, Heatran, and Suicune can survive a hit and KO it back. Gengar also can be very frustrating to use, as both Focus Blast and Will-O-Wisp have subpar accuracy and the inevitable miss can be catastrophic.