There had never been any particularly good method for transporting Gu Immortals across regions.
Because Gu Immortals had very little need for such things!
When Gu Masters ascended to immortality, the subtle differences in the Heaven and Earth Qi of the Five Regions caused them to become Gu Immortals of their respective regions—Northern Plains Gu Immortals, Central Continent Gu Immortals, and so on.
Gu Immortals themselves possessed strong regional sentiments, and foreign Gu Immortals were easily ostracized. In the final stage of the battle at Yi Tian Mountain, Hei Lou Lan and Tai Bai Yun Sheng had been hunted down by Southern Border Gu Immortals; this showed it clearly enough. In this regard, Eastern Sea was relatively open-minded.
Regional sentiment was not the key issue. The crucial point was that a Gu Immortal's immortal aperture had to be placed into the outside world at regular intervals, absorbing the outside world's Heaven and Earth Qi to stabilize itself. At such times, there were strict requirements for Heaven and Earth Qi. If a Northern Plains Gu Immortal placed their immortal aperture in Central Continent and absorbed Central Continent's Heaven and Earth Qi, it would cause trouble.
The third reason was calamities and tribulations. Gu Immortals faced calamities and tribulations without end—who would run around everywhere for no reason? Why go to another region? Unless there was an extremely important matter, such as a major immortal opportunity with clear clues, or a vital mission like Feng Jiuge's expedition into Northern Plains.
There was one point that needed to be distinguished.
Gu Immortals had little need for cross-regional transportation, but Immortal Gu and immortal materials were different!
The demand in that regard was still enormous.
However, Yellow Treasure Heaven had already greatly fulfilled these demands.
For all sorts of reasons, few people researched cross-regional