So what is a Kanshu, what are Jinki users and what's up with those weirdly coloured icons anyway?
Kanshu virus/Kanshu
Throughout this explanation thing, I'll use two phrases "Kanshu virus" and "Kanshu". The two mean separate things. The Kanshu virus is a virus spreading through the world. It kills its victims instantly (for the most part), turns their corpses into superpowered monsters (or "kanshu") who can also infect other humans and, from what we've seen, it also has an effect on memory. Not only will people not remember seeing a Kanshu after it's gone, but they will also not remember the person the Kanshu used to be. The latter effect is called "Lost Rebound" and how badly a person is affected depends on how well they knew the person beforehand. For example, a character gets killed at the end of volume 2 and Riku's guardian isn't that badly affected by it -- she just doesn't recognise their name. On the other hand, we see a girl whose boyfriend was killed and she practically goes catatonic. Canon says that victims of Lost Rebound do recover in time -- Riku's supposedly recovering from it -- but they'll always have these holes in their memory.
Understandably, it's very difficult for people to work out how many have been infected with the kanshu virus simply because they cease to exist in anyone's memory. They do, however, have an electronic record -- this is how the company that Rena and Youhei work for found out about them, as they work for an electronics company which has a phone carrier division. People were defaulting on their phone bills and when they tried to track these people down, they simply ... weren't remembered by anyone. It was discovered that phones tend to go nuts around Kanshu -- every phone in the vicinity will start ringing -- and that there was a way to fight back. Which, naturally, leads me to my second section!
Jinki Users
Jinki users are people who are infected with the Kanshu virus. However, unlike most victims who die immediately and then become Kanshu themselves, Jinki users are alive. This is because they possess a "core" or a ball in the centre of their left hand which arrests the virus. It's not a cure, however, and when this core is removed from a Jinki user's hand, they will complete their transformation into Kanshu. This is why Jinki users work in pairs; when one partner loses their core, the other must kill them. As to how one becomes a Jinki user, both times that this has happened in canon, the recipient was infected with the Kanshu virus, they received the core of an existing Jinki user and then their first act as a new baby Jinki user is to kill their benefactor ... who is now a Kanshu themselves.
A Jinki user gets all sorts of exciting benefits as a result of having a shiny metal ball in their hand. Their abilities are activated by saying the phrase "kensei", which generates a field like this. This results in certain obvious physical changes taking place -- marks appear on their faces, dark marks like gloves on their hands and their eyes change colour and appearance. This isn't all! Their vision's enhanced to a point that they can see on the infrared spectrum through walls, chances are their hearing is as well and their strength, agility and flexibility is through the roof. The absolute limit of their enhancements is dependent on the person in question and their own limitations. For example, Youhei is quite capable of running up walls and cutting them down with his sword, whereas Rena can stand on someone's head one handed and then spring off and cartwheel and backflip across a lake, up a tree and then land on the ground without breaking a sweat. They can also generate a "cage" or a barrier that is resistant to all conventional weapons. All of these abilities come at a cost though; a Jinki user can only use their abilities for a certain length of time. If they reach this limit, then they'll pass out and not be able to activate their abilities again until they've recovered. We have no idea how long this period of time is, only that Rena fought for most of the night and then passed out for a while and couldn't activate them for the rest of the fight. ONE DAY WE WILL GET DETAILS.
Finally, the Jinki users also are able to manifest a weapon. The weapon is unique to each user and seems to be related to their particular skillset and talents, as well as their individual outlook. These weapons are very useful for a number of reasons. The first is that they can penetrate the cages generated by Jinki users -- as one can imagine, this is useful when a Jinki user wants to actually hit something. The second is that they are the only weapon that can be used to kill Kanshu -- conventional weapons don't work. The third, which seems to be biting the protagonists in the ass a lot lately, is that when a Jinki weapon is used near a person, it means that they don't completely forget about the Kanshu attack that took place near them. This can cause Problems as (a) our protagonists kind of GO TO SCHOOL where they waged a pretty epic battle and (b) their fight is supposed to be in secret. Riku got dragged into the whole mess because he witnessed Youhei and Rena beat up a Kanshu and they kind of feel guilty about dragging a civilian into their epic fight. Considering that all of the Jinki users we have seen with canon ages are under the age of twenty, that's. Not surprising. Theirs seems to be a pretty short life. :'( And don't even get me started on Rena's Mysterious Backstory. s-sob why Moriyama.
What does this mean for you?
- Rena and Youhei are infected with a virus that is very fatal. The only reason why they are not dead right now is because there is a ball in their hands that keeps the virus from spreading.
- As a result of this virus, Rena and Youhei have abilities that range from heat vision to insane levels of agility, strength and flexibility to a resistance to memory alteration.
- They won't be talking about what they really do in camp, and while I can't speak for Youhei's player, if your characters are going to work out what they really do, then please let me know first and get my permission. It's not as bad as people knowing Steph's identity but it would make things complicated.
- We would really like it if they weren't killed. Like. Ever. It would be very awkward. Same with extracting their cores from their hands. It would not end very prettily. :(
- our canon is hot and you should read it.