He is the shadow of 15 different people at once, all of which converge into a singular entity. There are many who hate every single one of them and try to shield their eyes and block them out of their lives. But perhaps it is because they look at one of the personalities and recognize themselves. There is only room within for 15 personalities at once, but it switches them out from time to time so he is every single human alive at some point or another.

I skinned the bastard alive, put on his skin, and painted it like a clown. Would you like to see what I am underneath? If you do, you may never be the same again. Perhaps I shall take you to Thirteen's bones instead.