Here are some key things to remember:
* Location: Blackthorn City is located in the far north-east of Johto.
* Clair's Team: She specializes in Dragon-type Pokémon, with a team of Kingdra, Dragonair, and two Dragonite.
* Type Advantages: Fighting, Ice, and Dragon-type Pokémon are strong against Dragon-types.
* Prepare: Make sure your team is leveled up and has effective moves to counter her Dragon-type Pokémon.
* Story: You need to have defeated the Elite Four in Kanto and gotten the National Pokédex before you can challenge Clair for the ninth badge.
Good luck defeating Clair and obtaining your ninth badge!