William Miles may be the Mentor now, but once, he must have been an ordinary Assassin, the kind that goes on missions and the like. Plus, according to the wiki, he's in his 60's, which meant that he was a young man in the 60's and 70's, so he was alive and presumably active during some very interesting points in history.

So! The Adventures of Young William Miles: Assassin. Because there must be more to him than being Desmond's dad and the Mentor that we haven't gotten a chance to learn about. Things that made him who he is when we see him.

Anon isn't actually a very big fan of William, and would like a reason to...you know. Like him.