You have to get the key to the gym in Pokemon Mansion, but after you unlock the entrance, he is already inside there, so it's assumed that he's already in there even before you unlock the entrance.
The Gym Leader of Cinnabar Island in Pokemon SoulSilver and HeartGold is not on his island. His gym is set up on the Seafoam Isands. He has 7 trainers. Hope I helped!
You have to get the key at the end of the Pokemon mansion and press 'a' on the gym door.
In the beginning of the game, he isn't there. Towards the end, you will find his rival on cinnabar island by himself. After you talk to the rival, he leaves to go back to viridian. Fight the cinnabar gym leader, go back to viridian and the gym leader should be there. The man you talk to on Cinnabar Island Isn't the gym leader, but his rival. After you speak with his rival on cinnabar, the gym leader reappears in viridian. You have to fight and beat the cinnabar gym leader first.
Blaine is the gym leader in Cinnabar Island. When you get to Cinnabar Island the door to the gym is locked, you need to go to the Pokemon Mansion to retrieve the key. Once you have it you get to the gym and battle Blaine to get your seventh badge.
you have to meet gym leader from kanto in Cinnabar island
after Cinnabar Island you will surf going to Pallet Town or you can use fly to Pallet town or straight to Viridian City. the gym will open after defeating Blaine and after you get the master ball. upon reaching the gym leader, you will see that the leader is Giovanni, the leader of Team Rocket.
you catch it at mt.ember in one island. you will be able to go to one island after defeating blaine, the gym leader of cinnabar island.
Beat the 7th gym leader which is near cinnabar island and talk to the 8th gym leader which is on cinnabar island and he is going to go back to the gym to wait for you to challenge him.
You find him at Cinnabar island.
on cinnabar island
Defeat the Cinnabar Island Fire type gym leader Blaine Defeat the Cinnabar Island Fire type gym leader Blaine
get the key to open the cinnabar island gym
In the beginning of the game, he isn't there. Towards the end, you will find his rival on cinnabar island by himself. After you talk to the rival, he leaves to go back to viridian. Fight the cinnabar gym leader, go back to viridian and the gym leader should be there. The man you talk to on Cinnabar Island Isn't the gym leader, but his rival. After you speak with his rival on cinnabar, the gym leader reappears in viridian. You have to fight and beat the cinnabar gym leader first.
If you were a Pokemon series' character you could patch up with Ash and his friends to get to the Cinnabar Island team leader.
by beating the gym leader
The Cinnabar Island
in cinnabar island after you beat all 15 gym leader
He moved to the seafoam islands. That's east of cinnabar island.
You head to Pewter City and battle Brock there gym leader! Then from there you head south to Virdian City. There gym leader won't be there so you keep on to Pallet Town. Then pass Cinnabar island and head to the seaform island and challenge the gym leader! Then after you defeat there gym leader talk to the Virdian Gym leader at Cinnabar island and then you go defeat him at his gym