Yes, you can.
By beating the gym leader Clair in Blackthorn City.
You can't fight ash...only red
Go to the Dragon's Den on Mondays or Wednesdays, where you will see your rival. He'll talk for a bit, and afterwards, Lance and Clair will show up and engage you and your rival in a double battle.
You get to double battle Lance and Clair in the Dragon's Den after you have defeated your Rival in Mt. Moon.
Blackthorn Gym she leads with Dragon Pokemon.
Yes, you can.
from the game corner or dragons cave or from the temple after beating Clair
By beating the gym leader Clair in Blackthorn City.
No. But, you can fight them (as gym leaders) In Pokemon Silver/Gold.
Clair is in the gym in Blackthorn City
Clair is a cousin of Lance of the Elite Four. Claire's purpose is leader of the gym in Blackthorn City. Her purpose is to defeat the player. She is a major enemy in Pokemon. She is a boss! As gym leader, she will battle the player for the right to earn a new badge. Claire is most adept with Pokemon that are Dragon-type. She will fight the player with Dratini, Dragonair, and Kingdra in the Gold version, the Silver version, and Crystal.
You can't fight ash...only red
she uses dragon type Pokemon and she is the blackthorn city gym on heart gold (UK but available in USA) and Soul silver (USA but available in UK) soul silver and heart gold are both the same except the Pokemon!
go through the ice path to blackthorn city and beat clair tp get the 8th badge
Dragon's den in Johto, You'll then fight Clair and Lance with the Rival
You go to the cave behind the gym and answer the old man's questions in the shrine with compassion (you will need whirlpool). Then Clair will come in ,shocked, and will give you the badge. Then, you can go to New Bark town and sail east to the Pokemon League.