This mysterious Taoist was indeed the person who had previously destroyed the Jiuli heritage site, and was also the figure manifested by Elder Tan.
Lu Cang.
"I knew you would come back, but I didn't expect you to return so soon," Lu Cang said indifferently, "This time, you won't have the chance to escape. Hand over the Array Technique that controls this fountain source."
If the Magic Artifact had been refined by someone else, Lu Cang, with his cultivation, wouldn't have needed much effort to control it. However, this Underworld River Fountain Source was a Magic Artifact crafted by the Jiuli God, and without the Array Technique, no one could activate it unless their cultivation was higher than that of the Jiuli God.
Because of this, after Lu Cang destroyed this secret realm the last time, he was only able to seal it, unable to handle it any other way.