The area of each world was vast beyond measure. Sometimes, in a certain place, the power of the interface would undergo an abnormal change, and as a result, space would become thin, giving rise to a Spatial Vortex or a Spatial Rift.
Because of the Laws of Heaven and Earth, in the vast majority of cases, such situations were only temporary. Whether it was a Spatial Vortex or a Spatial Rift, neither was a true passage between two worlds, and as time passed, they would heal on their own. For example, not long ago, what Lingxu True Person had encountered was just such a situation.
But there were exceptions to everything. Sometimes, because of certain inexplicable factors, a fissure connecting two worlds would not close.
It was said that in a certain Human World in ancient times, such a thing had once occurred. For some unknown reason, one day, a Spatial Rift appeared and connected to the Demon World.
Because that rift was very small, it could only allow one or two Ancient Demons to pass through at a time.
Originally, this did not amount to much.
Even if those who came were high-rank Ancient Demons, when facing an endless stream of human cultivators, there would always come a time when their demonic qi was exhausted. In that case, although the casualties would be heavy, by relying on numbers, they could ultimately kill those Ancient Demons.
However, very soon, the human cultivators discovered something was wrong. Though this rift was small, for some unknown reason, it actually would not heal. Now the trouble was great.
Although there were not many Ancient Demons crossing worlds each time, they came in an unending stream.
Moreover, the ranks of these Ancient Demons far surpassed the level of the cultivators of the Human World.