For the people of the Jiuzhou cultivation world, and even the ones from the Divine dynasty, whether Xie Tian appears or vanishes is an extremely terrifying matter.
When Xie Tian appears, the Nine States will inevitably be stirred by him, creating wave after wave of terrifying tsunamis, with a force overwhelming enough that no one can escape.
However, the vanished Xie Tian, though unable to stir up tsunamis, makes people more alarmed.
Because no one knows what the disappeared Xie Tian is doing, what earth-shattering schemes he is plotting, and what drastic changes he will cause in the Nine States when he reappears.
To put it bluntly, for the bleak and desolate Jiuzhou cultivation world after the Lingjue Mountain incident, Xie Tian is nothing but a thief—
It's not the thief stealing that frightens, but the thought of the thief that does.
Moreover, they understand that no matter how powerful a force is, it's impossible to stupidly guard against a thief day after day.