How to Limit an Exposition Tool?

I've been tinkering with an idea that would allow a character to gain important information via a type of Vision Quest. In a vacuum, the idea is sound enough, the character gets information she needs and informs her later decisions accordingly. However, due to one of the elements of the story being trying to discover the origins/nature of the Big Bads, I need there to be reasons why not just anyone would use this method to find out anything they need to know.

First, some context. In this setting, the villains are people who use a God Guise as demons to make people think they're unkillable and, instead, use a method of sealing them away rather than kill them. That way they're set to cause their havoc again and again without risk.

One of the heroes is Ruby, a 13/14 year old girl and The Baby of the Bunch. I made a post about her a while back on the Hero Critique thread but, to spare some runaround, the basic gist of her character arc is discovering the cause of her mother's Parental Abandonment, leaving her in the care of a convent shortly after her birth and confront her mother over said abandonment.

A potential Show, Don't Tell method I thought of was a ritual that could allow Ruby to witness critical events firsthand via a vision. In so doing, she would have what could either be two visions or two halves of the same vision that reveal to her that her mother was mind-controlled into killing her first child in his infancy and, upon discovering she was pregnant, was flat fucking terrified of the same thing happening again. ^note A fear that is entirely within the realm of possibility because Ruby's race, as a whole, is vulnerable to a form of magic practiced by one of the villains allowing total control of them, with Ruby (precisely because of this abandonment, incidentally) being the sole known case of immunity.

Of course, given the nature of the setting's villains, that raises the question of why it's not used for them and what prevents casual use of such a thing in general? To that end I've been trying to think of potential limitations that would dissuade or actively prevent random people from exploiting this ability while still making it accessible to Ruby herself. Some initial thoughts:

• You experience these visions from the viewpoint of someone physically present. So you'll never know if a tree makes a sound if no one is there to hear it. That's a potential narrowing of scope right there. Especially if you don't necessarily have control over whose viewpoint you get. For example, the two portions of Ruby's visions are seen from the points of view of infants (herself and her brother).
• Borrowing from The Dresden Files, whatever you see you will forever have perfect recall of. Great if the vision is something pleasant or, at least, neutral. If something is traumatic? You will remember that traumatic moment exactly for the rest of your days. Even if you're a dotty old-timer in the grips of senility, this will never leave you. I imagine there coudl be a cautionary tale of someone wanting to learn who killed a loved one and got what he wanted, but saw the vision from the killer's viewpoint, so he has a perfect memory of killing someone he loved. This will probably be in regardless, as the perfect recall means Ruby can go over the vision and recognzie things (like spoken language) she coudn't have while experiencing it.
• I'm still a bit back and forth but one idea is that the ritual is Faith-Based. That would allow Ruby to know of it since she was raised in this religion. But also might have strong faith as a requirement for it. One belief I'd had more as a personal belief taught to Ruby but possibly coudl be added to the religion as a whole is that "miracles are reserved for those who truly need them", so only in that circumstance would this vision quest even work. Though part of me feels I should leave otu the cautionary tale, or note it as urban legend more than fact, if it's faith based like that.
• The last thing I was thinking is that there may need to be some bond or connection between the person whose POV you experience the vision from. Ruby is getting it from herself and her brother. That would pervent visions specific to the Big Bads pasts, since anyone who knew them is long dead after a few centuries of Sealed Evil in a Can shenanigans.

I think this covers most things I can think of. But I wanted to see if anyone else had thoughts or angles I hadn't considered.

Thank you in advance.

edited 7th Apr '18 11:14:23 AM by sgamer82

Whatever is providing the visions could have a mind of its own, only providing information about currently relevant things. For instance if a character holds a material that they don't know the properties of, they are provided with that information, assuming that those properties are widely known/not secret/whatever other justification fits.
The visions could also be stingy about their information, only revealing the bare minimum, requirng maybe a more specific situation to reveal more.
As for why the villains aren't using it, the simplest way to go about that would be that they just don't know that it even exists, maybe it being used a long time ago and then being forgotten. Maybe they did use it before and were disappointed by only getting limited information, then casting it aside and never "wasting" a thought on it again.
Naturally any of your limitations can be slapped on top of what I said here.

It's less "the villains don't use it" and more "why don't people use it to learn more about the villains?" Their whole schtick is a kind of God Guise that, once it's exposed, changes the playing field. So there has to be a reason why it wasn't exposed before the protagonists pulled it off. Past deaths among them, were hidden by total destruction of where the death occurred so people either don't know what happened or assume that even if you did kill them they'd self destruct and destroy everything around them.

Limited information is definitely a factor. A lot of it might have to be analyzed after the fact. In Ruby's case, her visions came from the viewpoints of babies. So for example, within the vision, Ruby wouldn't understand what people are saying when they speak because an infant wouldn't. Only later does she go over things and become able to pick up details, such as the discovery that her brother was deaf, as his side of the vision featured absolutely no sound whatsoever. A detail that okay heavily into how/why her race is subjugated by the villains.