Relics of a Saint
Hengye Zhen or not, there was not an individual that Xinzi despised more than Shenzhuo. With that man, he didn't need to apply logic, reasoning and whatnot. He had no use for context or excuses, simply looking down on him like an arbitrary despot would a crawling worm.
Still, in his bid to play the loving father, Shenzhuo gave Xinzi two pieces of crucial information. First, there could only be one Glorious Eye of Heaven and one Dark Eye of Heaven. The two stemmed from the soul, and should exist in any body that the owner's Divine Soul inhabited. This meant that the Glorious Eye of Heaven in Xinzi's Zhen-body was, either a copy based on Shenzhuo's genetics, or an incomplete product still in the process of awakening.