User blog comment:Xilinoc/Ch. 549 - The Stormbringer/@comment-8669536-20130917142828/@comment-11051098-20130919150340

If BG9 had another letter, I can think of a few epithets that could suit him.
 * C - "The Cold/Coldhearted", "The Cruel"
 * E - "The Emotionless" - can actually be Bambietta's epithet

I think the most logical, based on what we have seen, would be
 * The Killer (Lemursrule's idea)
 * The Knowledge (Ginhikari's idea)
 * The Kinetic ?
 * possibly even The Knight ? (Will-O-Wisp's idea)