go to the seafoam island you need all legendaries even arceus (real arceus to get there).no i just kidding just go to seafoam island if you dont know look at your map.you find a stair with ice inside seafoam island (east)and a ladder and go up to the ladder and you find the gym
You go to Seafoam Islands
Not enough info: which gym leader?
The final gym is the Viridian City Gym. Blue is the Gym leader.
you have to go to sea foam islands and that's where he is
Janine I think
The eighth gym leader still awaits, as well as the whole of Kanto.
defeat all the other gym leaders
Blaine.
Firstly, have to defeat the 7th gym leader. Then you go talk to the trainer next to the Pokemon center on Cinnabar Island. He is the 8th gym leader of Kanto, Gary. Gary is in Viridian City.
the 7th gym in Johto is in Mahogany town. And in Kanto the seafoam islands.
You beat the 6th gym leader.
he is Brock. hes in pewter city.
It's right next to the dojo in Saffron City