well,i only know what to do in soulsilver but its probably the same. you have to go on the teleport/forwardy things in the gym until you get to the gym leader i hope this helps
In her Gym
lugia, latios, and umbreon
Lyra gets the last Pokemon
4 Clair get a Pokemon with a ice/dragon move clairs Pokemon: GYARDOS DRAGONIAR(X2) KINGDRA. 4 blue his Pokemon are: EXEGGUTAR PIDGEOT ARCANINE RHYDON MACHAMP GYARDOS.
first get the first 15 badges, then go to cinnabar island, go up the steps to the left of the Pokemon center, and he's there, speak to him and he will leave for his gym.
She uses Dragon-type Pokemon, so use a lot of Dragon, Steel, and Ice-type moves. Electric-type moves will murder her Gyarados and Kingdra. :)
Go to the radio tower in Goldenrod and defeat Team Rocket (remember to go to the underground photo shop first).
go to the last city you gone to
from the kimono girls i think after... you beat the last gym leader
use multi type Pokemon
In the Lighthouse near the sea. Go to the last floor and talk to Jasmine the Gym Leader of that town
you catch it behind the last gym leader of johtos gym in the dragons den