The Barrier (結界; Kekkai) is found in Genso Suikoden: The Woven Web of a Century.
Description
300 years before the time of the game, hordes of Telluspharma suddenly appeared, destroying people, towns, and nations. Everything was on the verge of disappearing. A group of wise men drew upon the power of magic and stretched a barrier that would stop the Telluspharma. However, only a limited region was protected while everything outside of the barrier was destroyed by the Telluspharma.
This barrier was thought to be an "iron wall" but unfortunately it had a fatal flaw. Once every hundred years, the boundary becomes unstable, and the Tellupsharma are able to enter through the space in this distortion. This is the reason that the monsters that appear every hundred years are called the "Hundredth-Year Monsters".
The barrier stretches across the known world in game. When people approach the barrier, such as a path in the Wyvern's Nest or in Mt. Hioni West, they seem to walk in a loop. This is the power of the barrier - it not only keeps the Telluspharma out, but also keeps people inside.
Only some of those that have mastered magic (such as Astrid and Zephon) are able to intentionally open a hole in the barrier and see a portion of the outside world.
Some believe that should the Holy Aionian Empire fall, the barrier will also fall, which would mean the end of humanity.
Sources
- Genso Suikoden Tsumugareshi Hyakunen no Toki The Complete Guide (Japanese) (page 240)