I propose 6 on 6 Magikarp tourney.
I probably won't host it, so first person to post here can take those rights. I just wanted to come up with the idea.
PROTIP: Lvl 100 Magikarp can be caught somewhere. I forgot though, but it's not in my game...
You can capture LV100 Magikarp in Platinum in one of the areas that you get access to after beating the Elite Four. It's either Fight Area or Resort Area. There's this pond where all of the Magikarp are at insanely high levels. Someone correct me if I'm wrong.