Tumnus, take a Clefairy. The only moves it may ever use in battle are Metronome and Sing, its two remaining moves must be Strength and Flash, but it may never use them in battle. To evolve into Clefable, it must solo the last 5 Gym Leaders in the game. Then you must find all Moon Stones in the game (I think there are 5 in total, and I think at least two are hidden), sell four of them and use the last one to evolve it. You may then not use it against any trainers in Victory Road or the E4, but it must be your lead when you face your Rival in the final battle. If you take nicknames, name it Spaceborn.