Wallace

Wallace (Japanese:ミクリ Mikuri) was once the Gym Leader of Sootopolis City, the champion of the Pokémon League, and currently a Pokémon Coordinator. He is dressed in white clothing and has light blue hair. Among all the -type Pokémon he specializes in using, Milotic is one of his strongest Pokémon.

In the games
Wallace is the gym leader for the Sootopolis City Gym in Ruby and Sapphire. Wallace steps down as a gym leader in Emerald and gives the position to his former teacher Juan, and replaces Steven Stone as the Champion. Wallace specializes in -type Pokémon and has Milotic, Gyarados, and others.

In the anime
Wallace is a Pokémon Coordinator and once a gym leader and a champion before. He is found on Lake Valor with his Milotic. He encouraged Ash to participate in the Wallace Cup with his Buizel.

Wallace is one of the four judges in the Wallace Cup. Each time a participant completed his appeals (except for Jessie or Jesselina), he stood up and stretched out his hand while explaining just how beautiful the appeal was.

Wallace awards Dawn the Aqua Ribbon when she wins the Wallace Cup.

Ruby and Sapphire Arc
He agreed to be Ruby's mentor when he saw that Ruby was actually good at Pokémon battles, even though Ruby was hiding it.

Afterwords, when all Gym Leaders had a meeting, they talked about which Team was good, Team Magma or Team Aqua. Though in the end, both Teams were causing mayhem in the entire region.

Trivia

 * He is the only Champion who actually sticks to his strategy.