Loooong time lurker here. I've been reading X-Books for quite some time now and as far as I can remember, I was always fascinated by Nathaniel Essex. The thing that intrigued me the most was that symbol on his forehead. I've read somewhere that it's a bullet wound that cauterized.
Could someone point me to an issue (or a TPB) that explains the origin of this symbol? I know that this question has probably been answered a few times already.
Appreciate any help.
Long time Marvel fan