Gym leaders, Champions and notable trainers from previous Pokémon games will make appearances in Pokémon Black and White 2 and you’ll be able to battle against them in the new Pokémon World Tournament.

Run by the Sinnoh region Champion Cynthia, the Pokémon World Tournament is a new feature simlar to the Battle Tower/Frontier/Subway from past games, where players run through a gauntlet of challenging trainers.

The trainers confirmed to appear in the Pokémon World Tournament are:

• Brock (Pewter City Gym Leader)
• Misty (Cerulean City Gym Leader)
• Lt. Surge (Vermillion City Gym Leader)
• Erika (Celadon City Gym Leader)
• Janine (Fushia City Gym Leader)
• Blaine (Cinnabar Island Gym Leader)
• Giovanni (Viridian City Gym Leader/Team Rocket Leader)
• Blue (Viridian City Gym Leader/Kanto region Champion)
• Lance (Kanto Elite Four/Johto region Champion)
• Steven (Hoenn region Champion)
• Volkner (Sunnyshore City Gym Leader)
• Cynthia (Sinnoh Region Champion)
• Akuroma (Pokémon Professor)

Source: Serebii [via Siliconera]