...he's interested nonetheless are there books about it?

...There's a book about it.

He is interested.

Causes, symptoms, treatment?

All of the above?

Occasionally a powerful Gormak or Voss will leave behind an echo when they die, retaining their memories and skills. If this echo is disturbed by the unwary, it may take up residence within them and try to influence their behavior. Symptoms can include sudden mood swings, irritability, impulsiveness, paranoia, shortened attention span, and drastic personality drift. The treatment involves opening the patient's mindscape so the intruder can be confronted and expelled.

........is that so.

Yeah he wants to study that.

That might prove a little difficult. Opening the mindscape requires the cooperation of a Gormak shaman.

Really? Why?

That's not a question this book has an answer for.

Well, does the book at least say why it has to be a Gormak shaman, in particular?

Something about complementary knowledge.

...seriously? And they don't, like. Want to learn this other stuff?

Is there a reason why or do they have a silly rift like the whole Jedi/Sith deal?

(Of course they have a silly rift.)

The Gormak are tainted, and by extension, so is their knowledge. This ritual is the only instance where cooperation is permissible, due to the serious nature of the malady. And again, no recorded incidents in the last thousand years.

By the stars why is everyone so stupid.

Well. He'll learn what he can, he supposes, and then try to find Occlus again.

Here's the Voss part of the ritual. He'll have to go to a specific sacred site to make contact with a shaman. The book advises him to go in force, and bring the patient along if feasible.

Well it's not like he can do that before he's, you know, at least done enough with all of this that he can actually go fetch Occlus.

It can be put on the back burner for now.

He is asked if he feels he is ready to start vision training.

How can he tell?

Does he understand the rules by which visions are followed and their importance?

Cognitively, yes. He's not sure he agrees with the way Voss society treats them, but he's also not sure he's going to actually mention this part.

Then he's as ready as he's going to get.

Apparently so!

The vision trance is hard. Managing the freewheeling lack of control over the direction of his thoughts that will allow the hook of the vision to set in while maintaining the necessary meditative focus to have enough strength in the Force is no mean feat, but he'll also need to stay lucid enough to remember what he sees. Many Mystics use chemical assistance to achieve this state.

Hmm... what sort of chemical assistance? And does it work on humans?