For Tornaments, and Events I think it would be cool to have some special Pokemon.
Could be as simple as Surfing / Flying Pikachu to where Pikachu knows Surf or Fly.
Or more like Spikey eared Pichu with a sprite variation.
Could make up some based on other Pokemon properties as well, like a crystal Onix which can be a normal Onix with a weakness to fire intsead of water, know surf, and possibly have a custom sprite.
Or a squritel with shades, or a Syther with fly.....
To insure peopledont just sell these for 9999999999999999999¥ you could make them untradable if nessasary.