Makai Knights and You: also known as an infodump.

So to help people out in understanding just what the hell I'm talking about half the time with regard to in-universe references for Ryuuga, I've taken it upon myself to put together a bit of an FAQ page to help people out. A lot of this is probably going to be rehashed from the series wiki, but it's now all in one place and hopefully will be comprehensive enough to make things a bit easier for everyone. SO WITHOUT FURTHER ADO, LET'S BEGIN.

• What are Makai Knights?

Short answer: Demonslayers. To be a bit more specific, Makai Knight duties extend to eradicating Horrors that come through to our world and cutting them down as well as eliminating any potential hotbeds for negative karma (also known as Inga) from becoming enough of a problem to create Gates for Horrors to come through.

• What are Horrors?

HORRORS ARE BITCHES okay no seriously take your standard demons and mix them up with Heartless and you have at least a basic idea on what they are and their motivations. Horrors range from your standard cannon fodder that are usually eliminated with little to no problems to some real nightmare-fuel inducing models to ... giant naked ladies with celestial gun turrets (NSFW).

Amemiya's smoking some good shit.

Anyway - their entire existence is summed up by the fact that they want to take the darkest parts of humanity's nature and twist it to eat them (some have particular emotions that they prefer their victims to have before eating them, and they act accordingly to make sure it happens). Horrors ... eat by essentially swallowing their victims whole in a lot of gruesome ways. However, Horrors generally don't appear in their true forms, though, they possess people first!

FUN.

Generally how they do so is through the Gates that were mentioned earlier - an excess of negative energy that builds up in an object has the potential to create a Gate that allows Horrors to cross over to our world, and in order to sustain themselves within the human world, Horrors must possess people. The process is painful and, most importantly, irreversible. It's been known to cause great pain to the victim in most cases, and depending on the specific Horror, could be a slow and painful deterioration of the soul or a quick death, both resulting in the Horror eating the soul of the victim and using their skin as a means to blend in among normal humans. Granted, once confronted, they tend to revert to more animalistic instincts, with few exceptions, usually coming from the higher-level Horrors.

• What tools do Makai Knights use to fight Horrors?

Makai Knights have an arsenal of tools to help them in their hunts, including but not limited to their armor, Makaiken (Makai Sword - though they're not limited to swords, there's also spears/tridents, bows, axes, etc. - funnily enough the latter two are introduced in Ryuuga's seasons), a Madougu (in Ryuuga's time, they're incredibly rare), Madou Lighter, and sometimes various magic gadgets given to them by Makai Priests.

• What is a Madougu?

A Madougu is a piece of sentient jewelry forged by Makai Priests that act as long-range detectors and advisers to the Makai Knight they have formed a contract with. Originally, most older Makai families had one assigned to each major bloodline, but due to the general decline of the Makai Order, they are considered to be incredibly rare. Ryuuga's Madougu, Zaruba, is not only the companion piece for the GARO armor itself, but also the "legacy character" of the series, having served every GARO user up until this point. At this point in the series, Zaruba only has been shown to do the most basic of Madougu tasks, with the exception of one addition thanks to Ryume at the end of the Goldstorm movie: the ability to return back to the central hub where Ryume stays from anywhere within Line City. (with the right magic know-how, it could be altered to work similarly in a game setting, but it will take a decent knowledge of magic to probably pull this off, considering that Ryume is no slouch when it comes to magic ability)

• What is a Madou Lighter?

The Madou Lighter is a really cool-looking lighter that tends to emit colored flames which usually match up uniquely with the armor of the Knight that uses it (Garo users have green flames, but there's been blue, red, orange, and even purple flames seen as well). These flames are enchanted, they don't act the same way as regular flames in some aspects. When they come into contact with an Orders Document, they not only burn the document to keep it from being traced, but it also allows the Makai Script to become visible in a manner similar to a computer display in front of the Knight, and they help sometimes power up a Knight by a technique called Blazing Armament, which is basically letting them light their armor/swords on fire to get a power boost.

But what is most useful from a Lighter is its ability to detect Horrors in disguise. When the flames of the Lighter are shone in front of the eyes of a normal human, nothing happens, but when it comes into contact with a Horror wearing human skin, that's when things get interesting. Disguised Horrors have their irises turn a sickly white-green color with Horror script surrounding the eyeball. They can't help this, it's a natural reaction to the flames. There's been one notable exception to this rule - a Madou Horror, but they're a whole other situation altogether and as of this point all of them have been eradicated thanks to Ryuuga and his comrades' efforts at the end of Yami wo Terasu Mono (his debut season).

• What is a Makai Priest?

A Makai Priest is essentially the mage to the Knight's warrior. They specialize in sealing spells and other magic to help aid their Knight comrades, and some even can seal minor Horrors with their abilities. (though many also have martial prowess - there's no shortage of Priests and Priestesses that can kick some serious ass - figuratively and literally.) What's interesting to note is that while men can be both Knights and Priests, women can only become Makai Priestesses. (one of the few gripes I have with the series tbh)They also, like some Knights, have different specializations: while some are essentially internal affairs, others specialize in forging Madou Tools for the Knights and others end up as wandering Priests/Priestesses that can temporarily seal away Horrors until Kngihts are able to do so permanently or can take care of minor Horrors on their own.

• What does the armor exactly do for a Knight? Are there any weaknesses of the armor?
  

The armor does essentially what's on the tin: it's a means of protection for the Knight, making them close to indestructible against most threats, though enough internal damage can knock a Knight out of its armored state. There have been cases where a Knight has taken someone into the armor alongside them in order to protect them, but it severely limits their mobility and they absolutely cannot let someone touch the outer armor itself. Some Knights also have alternate forms of their armors that activate under certain circumstances.

The biggest drawback to the armor, however, is the fact that a Knight can only access it for exactly 99.9 seconds. Any longer and they start to undergo Soul Destruction, and the armor literally starts to try and eat away at the user's body and soul. Generally this starts to slowly drive the Knight insane, as well as transforming them into what's generally called a "Lost Soul" version of their armor, which looks much more feral and dangerous. At that point, there's a limited amount of time where someone can forcibly disengage the armor (done by striking them on the emblem across their waist) in order to prevent the Knight from being consumed by the armor and turned into a berserker.

So in other words, while incredibly useful, most Makai Knights only summon their armor to finish off an opponent quickly.

• What is Soul Metal?

A McGuffin Okay but no really - Soul Metal is the series' staple magic material. It comprises the outer armor for Knights and also makes up their weapons as well. It's also really freaking weird in the sense that not only is a good chunk of a Makai Knight's training learning how to wield the stuff, it's also the fact that it has the ability to change weight depending on the user's will. For example, using another Knight from earlier in the series: While wielding twin shortswords, he can put them together and send them flying like a boomerang with no problems. However, if someone untrained in using Soul Metal tries picking up a weapon made of it, it's nearly impossible to lift without supreme force of will.

It's also worth noting that any Makai Knight who knows anything will refuse to let anyone touch their armor - Soul Metal is highly corrosive to the touch and will burn flesh. (this is partially why they wear full leathers - it acts as a buffer, though the inside of the armor is completely safe) Plus side is that the corrosive properties carry over to fighting Horrors as well - Soul Metal is known as one of the only things that can completely cut through Horror flesh and properly cut them down in-universe.

• What kind of training goes into becoming a Makai Knight?

A lot of it. Most Knights come from long-standing bloodlines in the Makai community and have been training as long as they can remember. Being adopted and especially at an older age is almost completely unheard of, though possible. In the past, there were legitimate Makai Knight training boot camps that would teach young candidates to properly fight, strategize, wield Soul Metal, learn survival skills, and use teamwork. In Ryuuga's time, it's unknown if they still existed in a diminished capacity or not - in other cases, such as Ryuuga's, a Knight candidate may be put through intense survival training leading up to a test to see if they're worthy of inheriting any sort of armor. For another specific example for Ryuuga, he started his Knight training at 7, had his final test at 17, and had been working as Garo ever since. (ages in the series are really goddamn vague, but during S5, Ryuuga's actor was 24 to give a bit of a frame of reference.)

I'll probably add in more later as people have other questions, but hopefully this'll help give people an idea on just what the world of GARO is like.