He really isn't a gym leader.
Anyways, start from Ecruteak City or Mahagony Town.Enter the entrance that is in the middle of the route where Mt. Mortar is located. It should be the one with the apricorn trees nearby.
Enter the cave, you should see a ladder, ignore it. Use surf to get across the water. You will use waterfall when you get to the waterfall. Once you climbed the waterfall, head to the entrance found north and like in the middle. Then in the next room, you will want to use surf, to the right and make your way further right and north. Eventually, right after you will head left, a bit south, and left again. You will see another body of water, use surf to get across. Keep using surf when you see the next body of water, you will want to get north, that is the goal. Take the ladder that is visible at the end of the path. In this area, go the gray area, make yourself go to the right, but head left when the path diverges left and right. In the left, it will be a lengthy walk. Take the ladder at the end, in this next room you will find that person you are looking for (to the right).
8th Gym Leader: Claire8th GYM Leader is Claire of Blackthorn City. She uses dragon Pokemon. Yes indeed Claire is the 8th gym leader in gold/silver/crystal and she uses dragon type Pokemon just like lance
pryce the ice type gym leader
in goldenrod city
you can't
defeat Whitney the third gym leader
In the mahogany gym
the fith gym leader in crystal is on an Island in the southwest of Johto. use surf to get to him
Sabrina
8th Gym Leader: Claire8th GYM Leader is Claire of Blackthorn City. She uses dragon Pokemon. Yes indeed Claire is the 8th gym leader in gold/silver/crystal and she uses dragon type Pokemon just like lance
pryce the ice type gym leader
You have to flirt with them first.
in goldenrod city
you can't
Morty. He has ghost type Pokemon.
liquid crystal? do you mean Pokemon crystal if its Pokemon crystal the levels are 19 20 and 23
At burned tower
It could be Blue or Clair.