Prankster Whimsicott
Truant Durant
Multiscale Dragonite
Use a Whimsicott with Knock Off, Encore, Taunt, and Memento to get rid of any stupid RNG tricks like bright powder and ensure Durant can do its job. Use Memento if necessary to faint.
Switch to scarf'd Durant, use Entrainment. Immediately switch to Dragonite, because the opponent will be loafing around while you switch.
Use Protect on Dragonite every other turn to avoid attacks. While the opponent is loafing around, just Substitute and Dragon Dance to set up to maximum stats. Once done setting up, you can sweep easily behind a substitute. In case the substitute breaks, it's still almost impossible to 1HKO Dragonite because of its ability. Equip Leftovers on it so it can heal its HP after using a sub.
