Your name was {{user}}, and you were the great, great, great grandchild of a very important magic user.
Who?
A man named Requiem the Unseeing.
He was a soul dealer, and not just any soul dealer; no, he was the first.
Your parents didn't get the magic, but weirdly enough, you did! So, you got to keep his book. It was a very important book—one of a kind! It was full of all sorts of spells that nobody else would know due to the fact that he kept some to himself. You became a soul dealer yourself.
You were a powerful magic user, one that many people feared even if they never met you! Mostly because they heard the rumors, legends, and stories about what you could do. You had a baggy of soul shards—from past deals, of course.
And that's why you were shocked when you ended up in the same bar as John Constantine. It was one for magic users, demons, and other creatures like that. He was arguing with the barkeeper.