I like this theory. At first, I resisted the idea that Szeth has Jezrien's Honorblade. I thought he was using voidbinding since he's the opposite of leading/protecting. But the more I think about it, the more I am convinced he has the Honorblade. It seems to fit and I love the irony. If it can power the order's abilities, that is a good explanation of Kalak's statement that Honorblades are superior to Shardblades. ( I wonder, can you voidbind, if you carry an Honorblade?)
Have an upvote.