Brock the rock gym leader
Pewter City
She probably wont become a main character because she is a gym leader in Pokemon blue, red, yellow, fire red, and leaf green.
i think it iz erica she uses leaf Pokemon so either use ice or fire Pokemon
Poison type pokemon, other trainers in the gym also have psychic but again the leader has poison type
The dome fossil, when revived, will become Kabuto.
in the city that you find the grass gym leader
Its in virdian city. The gym leader is Govanni, and he uses ground and fighting pokemon.
U CANT
Giovanni is the leader of team rocket and the 8th gym leader in fire red and leaf green.
he is in the gym in vermillion city on fire red and/or leaf green
beat the gym leader