If anyone's interested in a more complete reckoning of Mr. Tharka's past, I'll direct you all the way back to storyline #4, "Dust Bunny." We'll be getting some new information during this storyline, but the basics have been kicking around in the background here for more than seven years. As for Doc and his magic sword, that's a relatively recent development: check storyline #57, "Forgery," for all that.
Fifty-Nine - In Shining Armor