Kyogre

Kyogre has gotten upgraded in this generation. With Choice Scarf, it makes an excellent revenge killer. With Choice Specs, it strikes fear into its nemesis, Blissey, and also can 2HKO almost every Pokemon in the game. With its massive Special Attack and rain, Kyogre is truly one of the most fearsome sweepers in the Uber tier. Despite the lack of movepool, the sheer power of its moves compensates for that loss. Every Uber team must have a strategy against Kyogre, or it will easily plow through them. The fact that a Pokemon like Quagsire is viable for the sole purpose of beating Kyogre shows how much of a powerful force Kyogre is in the Uber metagame!