With Wallace being the Elite Four Champion, people have been wondering, whats happened with Steven, the Champion in Ruby/Sapphire. He ends up being in Meteor Falls in a new room after you beat the Elite Four.The Room is easy to access. You need Surf and Waterfall to get to it and you will see some ladders, follow them through and you'll get to a bit which has a ladder to the South West on a raised platform. This will take you outside the door you go in to the Steven Area. Follow it through and you'll see Steven. He will challenge you to a battle

Pokémon Trainer Steven Skarmory Claydol Cradily Armaldo Aggron Metagross
Lv. 77 Lv. 75 Lv. 76 Lv. 76 Lv. 76 Lv. 78