Board Thread:Questions and Answers/@comment-32556318-20170712153049/@comment-36009152-20200112205513

With Sika Madu searching for people to experiment on, it did come across that Yu was one such person. So maybe he was born, and became 'Yu' when exposed to that black substance which seems to be some kind of force that can trained (like a spirit version of artificial intelligence that be tweaked). So born biologically as a human with the seraph gene, and immortal in that more of him can be made, and his overall Yu personality comes from the memories stored in that black shadow creature (if it is alive to some extent)... maybe XD