Why is Vasher's name a "joke on his part" according to Denth?

[Atreides he/him]

I've tried connecting the other names that Vasher has gone by with the names of the other scholars, or at least with the ones Vasher has already taken care of, but I can't figure out what Denth means in Chapter 19 when he says:   “Vasher. He’s used it for a while. It’s a joke on his part.” Anyone have any insight?

[Green Hoodie Mistborn he/him]

I've been trying to put something together to figure this out, but I also have nothing and had never really noticed that part. 

 

May need to add it to the Ultimate list of questions for Brandon!

[Lightsworn Panda he/him]

Hmm... It's not an anagram of any of his past names (unless you count the "H" in the "the" in Peacegiver the Blessed). Maybe he stole the name from someone?

[Aonar he/him]

Off the top of my head, I'd say it refers to Vasher's permanently ragged and disheveled appearance. 

 

Vasher is an anagram for "shaver."

 

It'd be a slightly poor joke, but it's the only thing I can think of. (It's more likely something that won't make sense until Nightblood comes out.)

[Terisen he/him]

I wonder if it has to do with where Brandon claims the name came from in real life.  He says in the annotations that the father of his girlfriend at the time was named Vance and he tweaked it to Vancer and then Vasher (though, the editor notes that Vasher was a name he'd used in another story previous to that experience).  I wonder if Denth's statement is Brandon's way of winking at that playing on the name in the actual story.

[Windrunner he/him]

If there's an in-world reason, I assume it will be revealed when he meets Yesteel in Nightblood, since Yesteel would presumably get the joke.

[Xavien]

My theory is Vasher is a play off of Shashara, possibly a tribute to her, their marriage, his love for her or (my favorite) Shashara's love for him.  So since he also killed her, Denth would think taking this name "a joke on his part"