I'm just wondering where is the best place to level your pokemon to lvl 100? I've been battling elite four non-stop but that just gets really boring. Any other places you suggest?
See if someone has a lucky egg for trade before you go Chansey-searching (they already have a low appearance rate) Once you have that, anywhere up by the Battle area and routes 225 and up are all high level pokemon that give decent exp.
Stark Mountain's a pretty good place. It'd be easier to train there if you were training a water Pokémon since there's lots of rock and ground type Pokémon in there.