There's this weird magic system I've been tinkering with recently that's tentatively named "lumatics". I don't know if I'll be able to make this make sense to anyone else, but here goes. The concept is that there exists a collective unconscious, a network of the thoughts and perceptions that humans have regarding the world around them. These mental perceptions cluster together into mindscapes, which are expanses within the mental landscape that represent a core concept. Mindscapes are filled with thoughtforms, visible features of the mindscape that represent specific thoughts, ideas, and beliefs that people have about a concept. Most mindscapes are effectively infinite in scope, containing expansive regions grouped around different facets of a core concept. Each of those concepts is layered. So, the scape associated with a specific hat is really just one region within the larger scape associated with hats in general, and the scape associated with hats in general is only a small part of the scape associated with clothing or fashion. The largest, or most abstract, scapes that have been discovered, are called the Metascapes, and every smaller scape is nested within one of the three Metascapes. The Metascapes are Society, Nature, and Soul. Society is a representation of humanity, civilization, technology, relationships, nations, and so on. Nature contains ideas regarding the physical world, and Soul contains ideas that are based on mythology, religion, the metaphysical, and emotions. It has been argued that there probably exist only two Metascapes, the Intangible and the Physical, where what we call Society really exists between these, as an overlap of those two higher scapes, but so far this theory has yet to be proven.
Lumatists are individuals who have trained their minds to access the mindscapes. Entering a mindscape requires clearly visualizing the core concept, which is much easier to do with a physical object to tie it to. Extremely talented lumatists are able to enter more abstract scapes, but most are limited to scapes associated with specific objects, and generally need to see the object in order to project themselves into its scape. For the purpose of this discussion, I'm sticking mostly to mindscapes associated with specific objects, because more abstract scapes are a lot harder to understand. So, these concepts can be applied to an abstract idea, but it's harder to visualize how that works. Just remember that when I say object, that's because it's the most common scape that lumatists access. The same principles can be applied to a scape representing an less concrete idea or concept.
When a lumatist enters a mindscape, their physical body is rendered unconscious, and they find themselves in an abstract landscape of thoughtforms, which appear as objects and features that represent ideas that people have had or are having regarding that object. Some thoughtforms are common enough ideas that they become a consistent feature of the landscape, while other thoughtforms represent a specific thought that someone had at a certain point. The meaning behind a given thoughtform isn't always obvious, and it requires some practice to interpret them. By exploring a mindscape carefully, a lumatist can uncover clues about what thoughts others have had around a concept. As a concrete example, if a lumatist entered the scape of a knife that was used to murder someone, they could look for thoughtforms that would give them clues about the identity of the murderer. They'd have to know where to look, though. Movement through mindscapes can be accomplished on foot once you're in the right general area, but since each scape is infinitely large, it could literally take forever to reach the region you're looking for. Fortunately, lumatists aren't limited to physical forms of travel within mindscapes. With practice, lumatists learn to "think" themselves into the region they're looking for, projecting their mental self instantly across the scape. Scapes aren't strictly mapped in three dimensions, either. The same thoughtform may be found in multiple "locations" within the scape. For example, there are "regions" within a scape where thoughts that happened at a certain time are clustered, but one of those thoughtforms could also be found in a region associated with the person who thought it, and in the region associated ideas that are similar in nature.
Exploring a mindscape can allow a lumatist to uncover secrets and "read" people's thoughts, assuming they correctly interpret the thoughtforms they find, but that's not the only thing they can do within the scape. By removing or altering key thoughtforms in a scape, lumatists can change the way people perceive an object. As a simple, concrete example, by stripping away the thoughtforms from their gun's mindscape that make the weapon stand out and seem dangerous, a lumatist could temporarily make it seem harmless. However, over time the core concept of that object will bleed through, repopulating its scape with the thoughts of danger and harm. As another example, if a thoughtform representing a specific memory is destroyed or moved to a different scape, it will alter the person's memory of the event. You can't completely destroy a memory this way, because it's only one piece of that memory that you're effecting, but by altering that piece you can drastically change the emotion or context of the memory in interesting ways.
Every mindscape has a sentient inhabitant, called a Jinn, that is the embodiment of the core concept of the scape. The Jinn is represents the consensus belief of the central idea of the object that the scape is associated with, and Jinn have a create deal of influence over their mindscape. Bargaining with a scape's patron Jinn can help a lumatist to find what they need or alter thoughtforms on a large scale, but getting on a Jinn's bad side can be dangerous. It's possible for a Jinn to leave behind its own scape, but that's easier said than done. Most Jinn are extremely loyal to their mindscape, as it's their identity. To get a Jinn to cooperate, you have to understand its essence, its purpose, and convince it that what you want aligns with that purpose. If a Jinn leaves its mindscape, the source object becomes deadened; it doesn't stand out, people don't really notice or care about it, and they have difficulty recalling it as soon as it leaves their sight. But in order to leave a mindscape, the Jinn needs to enter another one. This generally causes problems, as most Jinn aren't very friendly toward these trespassers. After entering a new mindscape, a few different things can happen. Either an agreement is made, and the two Jinn inhabit the mindscape together, or they compete for control. If two Jinn end up coexisting equally within a mindscape, the source object permanently takes on concepts associated with the foreign Jinn's domain in the minds of those who interact with the object, but maintains its original purposes as well. If the foreign Jinn is permitted to stay, but isn't allowed to graft into the mindscape, then it continues to exist within the scape, but has no effect on people's perceptions of the object. If a foreign Jinn overpowers the patron Jinn, the foreign Jinn's traits completely take over, and the original Jinn is either destroyed, or drifts into a larger, more abstract scape. Replacing a mindscape's Jinn can be far more permanent than altering or replacing thoughtforms, because the Jinn's influence spreads across the entire scape. The effects of Jinn displacement can be extremely unsettling to the mind of an observer, as it creates a strange dissonance where an object innately triggers thoughts and associations that have nothing to do with its nature, if that makes sense. It's actually very difficult to subtly graft a Jinn into a foreign scape, because it usually just doesn't fit. For some purposes, this works perfectly. For example, by grafting a Jinn from a horror movie into a mask, that mask will trigger heightened terror in those who see it. It's easier to create subtle effects on perception, ones that aren't necessarily noticed by the observer, if you can convince the two Jinn, the original and the foreign, to work together, thus maintaining the normal associations while adding some of your own.
Soulscapes are extremely abstract mindscapes that are manifestations are a person's own internal thoughts about themselves, their identity, and so on. They are extremely difficult to access, and require a deep understanding of the individual before they can be entered. Those who are capable of traversing soulscapes can be extremely dangerous, because they tamper directly with the essence of who a person is.
Certain lumatists have discovered a way to create mindborn, beings that exhibit self-awareness and appear essentially as hallucinations within the natural world. They're similar to the aspects in Legion. To create a mindborn, the lumatist must essentially convince themselves on some level of the reality of their existence. The character must become real enough to the lumatist that they begin to feel independent from themselves. Once a mindborn is created, the illusion of their existence must be maintained. Anything that breaks this illusion threatens to destroy the mindborn. Unlike Legion's aspects, mindborn can actually see and know things that their creator wasn't present for, but they're incapable of effecting the actual world. Anything they "do" can be seen by the lumatist, but no one else. Some lumatists claim to have created mindborn that can be "shared", seen by more than one lumatist, but this has not been confirmed.
A theoretical mental landscape exists in the study of lumatics called a paracosm. A paracosm is an independent, mental world, like an extension of the process of creating a mindborn. Their existence has yet to be proven, and the difficulty is that even if they can be created, accessing them would be extremely difficult, because by definition they're not associated with any thoughts directed at the world around us. If Brandon Sanderson were a lumatist, his worlds would theoretically exist as paracosms, but even then, accessing them would be another matter entirely. Entering the mindscape of an idea that inspired a part of a paracosm is not the same as entering the paracosm itself. Many lumatists have attempted to create paracosms. Most have failed, or at least failed to prove they actually exist, but those who have come closest have all fallen into a permanent trance, lost somewhere in the expanse of the mindscapes.
The Anomaly is a theoretical catastrophe that could happen if the general population knew about the existence of the mindscapes. This is the reason, in my world, why only a select few know about the magic, and why they maintain secrecy. The Metascapes are based on public perception of the way their world works. If knowledge of the mental landscapes become widespread, this could create a fourth Metascape, one associated with the mental world itself. There are a number of theories as to what would happen in the event that this happened. Some argue that nothing bad would happen, that the new Metascape would behave similarly to the other three. But others argue that a scape associated with the mindscapes could cause distortions in the fabric of the mindscape with unpredictable results. It might become dissociated with the natural world entirely, plunging anyone who's mind touched it into a mental abyss, it might create ripples throughout every mindscape that infinitely warp and distort the mental landscape into a tangled mess, driving everyone insane, or we might all just die. Depends who you ask. Everyone pretty much agrees that they'd rather not find out, though, and so the lumatists remain in the shadows.
EDIT: My main setting for this includes a version of myself, not a lumatist himself, within the setting, who thinks he's the real me from the normal world, and so has inadvertently has created an infinite number of nested paracosms, each with a little mindborn version of me thinking that he's the one who came up with the whole concept, totally unaware that he's actually living inside a paracosm himself.