Countless ages ago.
It was when Chi Yu became Xuan. He shed his body and transformed into Xuan, yet unbeknownst to him, a trace of corrupted origin left his body and fled, hiding within the darkness.
This was Xuan's dark side, the darkest and most evil, the ultimate evil.
As Xuan himself, he remained unaware of this matter. It was only eras later, when Xuan became invincible and bored beyond measure, that he began playing that game of experiencing mortal life and reincarnating on Earth.
This gave that trace of dark origin an opportunity. It secretly took on Xuan's appearance, entered Mi Tu Knows Return through supreme authority, and covertly released quite a few unstable-factor systems.
One of them was All Things Devouring. While releasing those systems, he also intercepted quite a few test subjects.
Xiao Long was fortunate enough to become the subject of Black Xuan's manipulation.
In truth, Black Xuan had also secretly bestowed the Mythical Great Luo method upon Xiao Long as an inheritance.
Black Xuan's goal was simple: he wanted to replace Xuan.
The same saying applied: both were Xuan, yet this era should revere This Seat.
Mi Tu Knows Return, Void, Cloud Dress, and a group of Elder experts investigated the Backstage Manipulator, but they were overwhelmed and utterly without clues.
"Alas, who on earth did this?"
"Could it be some unstable factor that developed self-awareness?" an expert in a white lab coat said.
"Impossible. Even if it developed self-awareness, it would still be controlled by the central system. It absolutely could not break free from it."
"Alas, then this is strange!"
"Could it be not the work of a person?"
Everyone froze!
"Not the work of a person? Then what could it be?"
"For example, a Source Doppelganger, a shadow manifestation, and so