The Luzet Mountains are visited twice during the story, the first is after Justin and the party return from Alent. The second is after Gaia attacks the continent. During the second visit the previously encountered monsters have been infected with Gaia's power and have become stronger.
After crashing down from Alent, Liete informs the party that Gaia is manifesting itself beyond the Luzet Mountains. After a quick trip through the Savanna Wilderness the party make quick work traveling through the mountains and arrive at the J-Base.
After Gaia's destruction of Zil Padon, Justin, Feena, Rapp and Liete once again travel through the Luzet Mountains fending off the now Gaia infected monsters. Upon entering the East section of the mountain range, the party see Gaia evolving beyond the J-Base.