Clairvoyance

Terminology
Clairvoyance: "the alleged ability to gain information about an object, person, location, or physical event through extrasensory perception." Linked somehow with magic. Unknown origins. Suspected to be an "evolution" or "mutation" of magic.

Clairvoyant: People who have clairvoyance.

"Dial down" technique: Often inbuilt reflex in clairvoyants to prevent an overload of perceived information. Vital to them not self destructing.

Lore
Stuff

Clairvoyants are not recognised outside of pureblood families. Little information is available about them. All accounts of their existence and the validity of it are behind lock and key and a couple of dragons.

Clairvoyance itself is linked with magic. However, Squibs and Muggles have been noted to have it. It is suspected to be of a separate "strain" of magic because of this.

The Imperius Curse is rumoured to have been created by a powerful clairvoyant. It was both for the sake of not being drained by their abilities and a good carpet to hide clairvoyants' existence under.

Clairvoyants would be considered a threat to society if more people knew of them. They control a specific brand of magic unique to them, similar to half humans and werewolves.

Traces of orders that were dedicated to killing clairvoyants in the past have been found. There's evidence to suggest that they exist to this day.

Governments worldwide publicly do not speak of clairvoyance. The eastern parts of the world have proved to be more aware of the situation but nonetheless deny it all the same.

Many suspect that a lot of "cold cases" are connected to clairvoyance. This extends even to the Muggle world.

Every case suggests that clairvoyance is a refined form of wandless magic. Like switching to Animagus form, it does not require a wand in all cases. There have been cases, however, where it's been claimed that use of other magic (wand, potions, enchanted objects, etc.) can affect and possibly amplify it.

Branches
I don't agree with the idea that we gotta go "oh there are only 3 branches of clairvoyance!!" because imo that's not how that works. It's really limiting and kind of ??? doesn't work with the HP magic canon like no magical person in HPU is limited to some type of magic (barring magic that's banned by law). Clairvoyance should be considered a form of magic, albeit a very odd one since it's of a very individual form.

— Born: Born with. Hereditary. In their genes. Have a chance of passing it on to their children.
 * — It's difficult to guess if they're born with it. The process involves looking into the person's family records, since clairvoyants are similar to metamorphmagi in that both are often hereditary.
 * — It's part of why tracking down clairvoyants and keeping an eye on them is nearly impossible. While they are far more common that people believe, not all clairvoyants know they are clairvoyant since some manifest in the smallest of ways. Entire lines of clairvoyants can be and have been overlooked.
 * — Clairvoyants themselves do not always have the capability to pass this magic on. It's akin to purebloods having Squib children, and Muggleborns cropping up centuries after the last actual magic person in their family had died.

— Developed: Either unnaturally received or are the first person in their family line to have it. For OOC's sake, they pass it on more rarely than known clairvoyant lines. Also OOC: descendants (and current living relatives) manifest a higher resistance against clairvoyance than that of any other person.
 * — While not in known magical history, people have been trying to 'replicate' and 'force' clairvoyance out of people since who knows when. Sometimes, there are results. Cruel mental experiments and the like have been carried out on victims, who don't always survive the procedures with an intact mind.
 * — Development has been linked with the person undergoing serious trauma, stress, and lifee altering circumstances. It's where the whole "torture" thing came up as an idea for the people wanting to create more clairvoyants. I based this after a number of factors in general superpower fiction. See: Heroes, X-Men, and recently, Deadpool.
 * — People who 'develop' clairvoyance can either be the most dangerous (more on this later) or the least problematic of clairvoyants. Developed clairvoyance is known to hit maximum potential almost immediately unlike hereditary clairvoyance, which can take lifetimes. However, unlike hereditary clairvoyance, their beginning is their absolute limit and can no longer go beyond it.

— Two types of hereditary clairvoyance
 * — Immediate. More common in families studded with clairvoyants. OOC wise, being surrounded by fellow clairvoyants of their blood allow clairvoyance to manifest along with their magic in a calmer, more controllable way. Their first few signs of magic are linked to clairvoyant abilities. It disappears for the most part after that, since their subconscious employs the dial down technique in order to 'prepare' the person's brain as they go into puberty. A common problem to find is that without clairvoyant mentors to tell them of this, the user goes into their adulthood in blissful ignorance that they are in fact, clairvoyant. The 'dial down' technique is permanently embedded in them for the rest of their lives if they do not actively recognise their abilities.
 * — Irregular. The most common type of clairvoyant. They show zero signs during their first acts of magic. Instead it triggers under extreme duress. Commonly appears during puberty. They usually never make it past puberty, since a dysfunctional aspect of this is that the 'dial down' technique is ineffective for them to manage it. It has known to slowly chip away at their sanity and make them prone to loss of control. Very few actually make it through the mental training regimes (if they find someone able to teach them or on an even smaller chance, learn on their own). Their clairvoyant abilities tend to be intrusive and can be used offensively, which makes it all the worse if they're left loose. They are not recognised as a serious problem since morbidly, they kill themselves early in to end the mental exhaustion.

— Two types of developed clairvoyance
 * — Naturally developed, evolved. Means that they set the power bar for their future descendants (who will be hereditary clairvoyants). This gives way to them gaining a ridiculous power surge that can quite possibly kill them before they even reproduce. That's why clairvoyance isn't really a common thing despite being hereditary. Unlike the Sight and Metamorphmagi abilities, which skip generations, clairvoyance doesn't 'prepare' the bloodline at all and spreads to everyone like a parasite. It culls out those who are incapable of handling it. Pretty bloodthirsty.
 * — Coincidental development. Means the ability was forced out of them against their natural magic flow. This only applies to people who have been experimented on. Because of its unnatural development, it's the most volatile and most dangerous of all types. Clairvoyants who have it are known to have a total incapability of using the 'dial down' technique, a technique that's either inbuilt or natural to any other clairvoyant. The technique in question keeps them sane and comes with the clairvoyance package. Such is not the case for this type. They often share the same fate as irregular hereditary clairvoyants: an early death. They, however, do not need to take their own lives since their own brain shuts down on them. Their torturers do not care about this, since they last long enough for more experiments. There is no, IC verified way to stop their brain from completely shutting down.