The skeletons, as well as the Baron, seem unaffected. Though you can't be absolutely certain as far as the Baron is concerned, the skeletons appear to be mindless, given that they don't do anything without the Baron's commands, while the Baron him/herself seems protected by something else altogether.
"You guys focus on the Gashadokuro! I'm going to handle the Baron."With that said, Matsuko dashes upwards, unleashing a barrage of hell on the giant skeleton that the Baron is riding.
[spoiler]Yes, having two halves of different brains apparently protects you from mind-affecting stuff.
From this point onward, consider that Matsuko and the Baron are engaged in "cinematic mode". Kyx should be able to tell all of you that you're going to have your hands full just dealing with the first big guy.
In case none of you can tell, this is my way of getting the combat-capable plot exposition NPC out of the way so she doesn't steal all of your precious, precious XP.
[/spoiler]