Gyarados

Unlike most Dragon Dance users, Gyarados has great bulk and Intimidate, which allow it to set up more easily; however, this comes at the cost of its Speed, a painfully slow base 81. Like most physically oriented setup sweepers, Gyarados is heavily crippled by Intimidate, burns, and paralysis. When equipped with Gyaradosite, common Gyarados switch-ins, mainly Rotom-W, aren't a problem anymore due to Mold Breaker, which allows Mega Gyarados to hit the former for super effective damage. Its drastic type change with its Mega Evolution can allow Gyarados to better take on Rock-types and gives it an immunity to Psychic-types. Additionally, Gyarados has a pretty great support movepool, allowing it to perform either as a sweeper or a supporter.