Whimsicott is a mon I think counters the priority demons (Raging Bolt and Kingambit) pretty well.
Worry Seed and Encore with Prankster and this typing (and maybe a TeraFire every now and then) can beat a lot of mons that the rest of the team will appreciate. Speed EVs outspeed Kyurem and then the SpA and SpDef EVs are to beat Raging Bolt 1v1.
Hope you enjoy!: https://pokepast.es/3aa86a5b350db61a
Worry Seed and Encore with Prankster and this typing (and maybe a TeraFire every now and then) can beat a lot of mons that the rest of the team will appreciate. Speed EVs outspeed Kyurem and then the SpA and SpDef EVs are to beat Raging Bolt 1v1.
Hope you enjoy!: https://pokepast.es/3aa86a5b350db61a