Instructions
Defeat the other seven Kanto Gym Leaders in "Pokemon SoulSilver." These Kanto Gyms are located in Vermillion City, Saffron City, Celadon City, Fuchsia City, Cerulean City, Pewter City and Cinnabar Island.
Talk to Blue on Cinnabar Island. Blue is the Gym Leader of Viridian City and will not return to his Gym until you show him all of the Johto and seven of the eight Kanto Gym badges you have won. He is found wandering around outside on the small island.
Return to Viridian City and challenge Blue to a Pokemon battle inside the Viridian Pokemon Gym.
Bring a diverse team of Pokemon types when you take on Blue, as his Gym's strategy is to use many elemental types of Pokemon. This is a good strategy to use in any battle and if you have made it this far in "Pokemon SoulSilver," chances are your team already incorporates many different Pokemon types.
Defeat Blue's Pokemon by hammering his crew with attacks that are super-effective against them. Blue uses a Gyrados and Pidgeot; both monsters are weak against Electric-type attacks. A Pokemon that understands a powerful Water move should be able to handle Arcanine and Rhydon. His Machamp and Exeggutor share a vulnerability to Flying-type attacks. Switch out Pokemon as needed to quickly defeat Blue's Pokemon team for the Earth Badge.