Angels: Chi No Ryuu
Kigai Yuuto
The token playboy and one of X's most enigmatic and mysterious characters. Yuuto is handsome, charming, has impeccable manners, and is quite the ladies' man. He describes himself as a "simple government employee", but according to Arisugawa Sorata, he looks more like someone that works at a host club... in other words, a gigolo.
He is mellow and appears to be mostly amused at the world around him, and follows his path as a Dragon of Earth with no particular passion. In my opinion, it is precisely that lack of passion and involvement that make him a particularly dangerous man. He comes off as something of a dandy, and it effectively hides whatever his true motives may be... not to mention, it probably makes people underestimate him.
According to the X Character Files, Yuuto has a younger sister, but she's never been mentioned in the manga.
Lastly, Yuuto is actually a crossover character, and originally appeared in Hangun Seisenki.
Yatouji Satsuki
I often wonder if CLAMP actually set out to design Satsuki to be the embodiment of a computer geek's fantasies. In her late teens or very early twenties (it's not really clear which), Satsuki is a buxom, frighteningly intelligent computer genius.
She is also something of a sociopath.
Satsuki believes humans are boring creatures and feels no particular affinity or respect for the rest of humanity. She doesn't seem to care about or understand the feelings that move most people, and therefore has no particular compunctions about killing or generally using her talents to wreak havoc on society.
Other than Fuuma himself, Satsuki is the Dragon of Earth who has caused the most damage in Tokyo. She does this by hooking herself up to Beast, a somewhat sentient super computer that enables her to hack into any computerized network in Tokyo (meaning she can hack records or cause power outages with equal ease).
The only creatures Satsuki has shown any sort of rapport with are Yuuto (she seems to have a crush on him) and Beast (who seems to be in love with her and is apparently QUITE JEALOUS of Yuuto).
Nataku
The short explanation on Nataku is that it is a "genderless bioroid", an artificial but genetically perfect human. The long explanation is that there was a scientist who was was doing medical research to save his little grandaughter Kazuki from some kind of illness. The little girl died anyway, and her father (the scientist's son) vowed to bring Kazuki back with the cloning technology they'd been researching.
Since Kazuki's body had been too deteriorated by her illness, her father sacrificed himself so the grandfather could use his body for the "missing parts". (No, this doesn't make a whole lot of SENSE... but it's tragic! And angsty! And the bioroid is pretty!). In the end, the scientist used his son's body to artficially manufacture a genderless human who seems to have what is left of Kazuki's consciousness but outwardly resembles a male. Got a headache yet? No? Kazuki is supposed to have no conscience or feelings. It was named Nataku, after a chinese god that was created first out of wood and was later given a human body, but not a soul.
Nataku can sense the Shinken and was sent to retrieve from Togakushi Shrine, killing Monou Kyouga, the priest and keeper of the Shinken, in the process. As it left, Nataku saw Monou Fuuma rush to his dying father's side, and was struck by the resemblance to Kazuki's father. Later, when all the Dragons of Earth gathered around the Dark Kamui, Fuuma told Nataku that even though it was one of the Angels, it could what it wanted. Nataku replied that it wanted to remain by Fuuma's side, because Fuuma looked like its father. Bet you have a headache NOW.
Shiyuu Kusanagi
Kusanagi is the "nice guy" among the Dragons of Earth. He is a soldier in the japanese army and feels a particularly strong affinity towards nature. In the tradition of extreme envirnmentalist groups the world over, he cares so much about nature that he thinks people should be stopped, at all costs, from continuing to harm nature. Which is why he is a Dragon of Earth whose aim is to destroy humanity.
Kusanagi meets and befriends a young girl named Yuzuriha. She falls in love with him and he seems to develop feelings for her as well. She also turns out to be one of the Dragons of Heaven. I would say this implies a certain conflict of interest on Kusanagi's part.
I don't really like Kusanagi very much, as I'm sure is evident by now. I don't find him to be very interesting. However, Kusanagi is VERY perceptive man; in fact, he was able to sense and understand, in a way, something which lies at the heart of why and how Fuuma came to become the Dark Kamui.
Sakurazuka Seishirou
Suave, elegant Seishirou is actually the sakurazukamori, an assasin who uses onmyoujitsu to kill his intended victims. As the sakurazumori, Seishirou tends to kill those who endanger the future of Japan, but he has been known to kill for his own reasons.
"Sakurazukamori" means guardian of the sakura (cherry tree) barrow. Seishirou tends to create the illusion of falling sakura blossoms whenever he kills or uses onmyoujitsu in general. The fact that the sakurazukamori is linked to the sakura tree is particularly interesting, given that it's a national symbol: the sakurazukamori protects the sakura, which symbolizes Japan. It's equally interesting to consider that the sakura blossom is a symbol of life's ephemeral nature in bushido, the moral code of the samurai.
Contrary to popularly held "fanon", the sakurazukamori does NOT feed his victims' bodies and souls to a sentient, carnivorous cherry tree. This misconception arose from the fact that Seishirou, in particular, tends to dispose of bodies by burying them under a cherry tree. In Tokyo Babylon, and in typically cryptic manner, he asks the 16 year old Subaru if he knows why cherry trees have pink blossoms, and tells him it's because they feed on bodies buried beneath. While I can understand how people might interpret this as "feeding the tree", it must be pointed out that ANY plant would feed on the nutrients from bodies buried under them. More importantly, nowhere in X or Tokyo Babylon is it stated that there is A particular, carnivorous tree that the sakurazukamori must serve.
Be it a family trait inherited from his mother, the previous sakurazukamori, or as a result of being desensitized by his "profession", Seishirou claims to be unable to feel anything for another human being. To use his own words, kicking a person in the stomach is essentially the same as kicking as rock. The one exception is Subaru, thirteenth head of the Sumeragi Clan and traditionally the sakurazukamori's opposite, with whom he shares a dark and painful past.
Seishirou has no particular interest in the battle for the end of the world, outside the fact that it's brought Subaru back into his life after 9 years. He continues to go about his business as usual, but seems to enjoy Fuuma's company on the occasions that the Dark Kamui approaches him.
Spoilers to come.
Kuzuki Kakyou
The last of the Dragons of Heaven to appear in the story is the beautiful, ethereal Kuzuki Kakyou. He is a yumemi, a dreamgazer who can see the future in his dreams. He was completely isolated from the rest of the world because the government wanted to make use Kakyou's "gift". He was, in effect, a prisoner, and the one thing he wanted was to meet someone that would ease his loneliness. And he did. Sumeragi Subaru's twin sister, Hokuto, managed to enter his dreams despite having almost no talent as a medium herself.
Hokuto was a spark of life and light in Kakyou's dreary existance. She held her hand out to him and asked him to come outside, she believed that nothing was impossible. She gave him hope; and he loved her.
When Kakyou foresaw Hokuto's death at the hand of the sakurazukamori, he knew he couldn't save her, but tried anyway. He was shot while trying to escape his "prison" and went into a coma. After Hokuto's death, Kakyou lost the will to live.
Kotori managed to inspire pity in him, because she had some abilities as a yumemi and because he wanted to make her inevitable death less painful. After killing Kotori, Fuuma came searching for Kakyou and managed to break through his dreamscape. He asked Kakyou to "weave dreams for him", in other words, to guide him, in exhange for which Fuuma promised to grant his wish. Everyone believes this means that Fuuma has promised to kill him, but TRUE wishes being what they are in X, I have the feeling that Fuuma may end up granting his wish in some other way. At any rate, Kakyou has found found a certain comfort at Fuuma's side, and the Dark Kamui is at once tender and very possesive of him.
Kakyou is my second favorite X character, and Fuuma x Kakyou is my favorite pairing. Just thought I should let everyone know. ^^