Lazar wanted to break Hao Xuan's resolve so he would not be able to put up a resistance later or even think about escaping. He wanted to have full control over his mind. (Image in authors notes and discord)
He channeled a portion of his own willpower into Hao Xuan's body but upon coming into contact with the chaos energy it disintegrated into nothingness.
A hint of amazement flashed past his face but only for a brief moment. He refocused his energy, this time using almost 10% of it. It went straight for Hao Xuan's brain, trying to wriggle its way in towards his soul to create a soul contract.
To Hao Xuan it felt like someone had reached into the very core of his being, exposing every secret and insecurity he had in an attempt to 'undo' him from inside out.