To get the 8th Gym Leader to return to his Gym in Viridian City, you must defeat all 7 other Gym Leaders.
After u beat the first 7 u will go back to pallet town and then go to viridian and the gym that was earlier locked is now open (Giovanni is the boss)
Beat the first 7 gym leaders then go to the closed gym in Viridian and it will be opened.
You get it by beating Giovanni at the Viridian City gym, which you can't do until you have the other 7 badges.
you dive to get to sootopolis which is in the south east from mosdeep then fight groudon then you can challenge the gym leader and get your 8th gym badge. then u challenge the elite 4.
The Only Way To Get Into The Gym In Viridian City Is You Have To Beat All 7 Of The Other Gym Leaders Along With Beating The Leader Of Team Rocket.....As Long As You Have Strong, High Level Pokemon You Can Beat Him...Hint The Leader Of This Gym Is Also The Leader Of Team Rocket Giovanni.....
To get the 8th Gym Leader to return to his Gym in Viridian City, you must defeat all 7 other Gym Leaders.
She goes back to the Cerulean gym to be the Gym Leader
Defeat the 8th
The 7th leader is Candice in Snowpoint City
The 7th badge/gym is in Mahogany Town. The Gym Leader mainly has ice type pokemon.
After u beat the first 7 u will go back to pallet town and then go to viridian and the gym that was earlier locked is now open (Giovanni is the boss)
you find it in the Pokemon mansion
In Mossdeep city I think.....
hes in the seafoam isands
beat the other 7 gyms in kanto and talk to the 8th gym leader on cinnabar island. he will leave and go back to the gym
Maybe depends on what you have dark types are good against the leader.