Su Lie could actually detect the 'realness' of Gu Hang.
When he appeared, he didn't seem like an illusion. Although he had a strong Spiritual Energy reaction, it was distinctly different from a demon and didn't resemble a demon's disguise.
Before this, illusions created by 'It', or demons that listened to 'Its' instructions and disguised themselves in various forms before him, were all different from the current state of Gu Hang.
Moreover, the Spiritual Power used by Gu Hang was violent and fierce, yet it lacked the disturbing, nauseating, and inexplicably desirable wicked feeling of a Subspace Demon. On the contrary, it even seemed to cleanse evil.
These qualities aligned with the legitimate Psychic from the legends about Gu Hang.
Even though he noticed these things, he was still afraid to believe.
