Teito wears a black suit with gold lining and has bright green eyes. His hair is brown and cut short. He has also been seen wearing Bishop robes after joining the church.
At the beginning of the story, Teito is a cold and serious student, even to Mikage, although they are good friends. This is understandable, as his only memories were of being a combat slave whose only purpose was to kill criminals when he was very young. Even so, the chairman once said that Teito's compassion is his greatest 'weakness', despite all the hardships he has gone through.
Though in the manga, he's shown to be more expressive. He usually has loud outbursts and seems to have a short temper.
His ideals are solid as people have a hard time making him waver. Proof of this is when he escaped the brainwashing of Nanase and his scientists.
Teito was a former slave captured by the Barsburg Empire and considered to be the military academy's star pupil. Teito's homeland is the former Kingdom of Raggs, and he was raised as an orphan in a church. It is later revealed that Teito had been entrusted with the Eye of Mikhail when the Empire invaded his home country, and he is the son of the former king of Raggs, Weldeschtein Krom Raggs, thus, a prince. His real name is Wahrheit Tiashe Raggs. He is later revealed as the container for Pandora's box.
Teito is very agile and an excellent runner after having trained with Castor's puppets, and manages to get through the examinations on his first try with Hakuren.
Teito has an offensive Zaiphon, which he used to handle the zaiphon powered weapons. Teito is very skilled with the Baculus, exceeding the Zaiphon limit for it during training in one incident. He is said to have a very powerful Zaiphon even on its own.
Frau- Frau saved Teito's life when Teito falls from his hawkzile while escaping from the empire, the two afterwards developing a deep bond. Frau often teases Teito about his height to which annoys Teito a lot, despite this Frau also keeps Teito's spirits up with by encouraging and consulting him and Teito sometimes makes associations between Frau and his late 'Father' (Fia Kruez) because of this. Whenever Teito is always in danger and being targeted by enemies kors he is the always the first who come to his rescue. Although Frau enjoys teasing and annoying Teito about how he looks like a small child, he is still considerate about Teito and cares for him as seen when he searched for Mikage's reincarnation for three days and stopping Castor from erasing Teito's memory of seeing him as Zehel, stating that if he (Castor) was to wipe out his memory as Zehel, he will also be wiping out Mikage's last smile which he believes is Teito's last treasure of Mikage. Frau also accidently becomes Teito's "master" when he tried to remove the slave collar on his neck, this collar gives Frau the ability to use three commands on Teito: bind, sleep and pain. Since the two of them cannot be apart from each for more than fourty eight hours, Frau accompanies Teito on his journies to visitng the 7 Districts. Teito has intrusted his life to Frau, and if he were to be taken over by Ayanami (to retrieve Pandora's Box) then he requested that Frau were to kill him before Ayanami succeeded. Which Frau were reluctant to even agree to, nonetheless only agreed to do so to put Teito's mind at ease. Frau often calls Teito "brat", which makes Teito extremely flustered and angry, in which he replies, "perverted bishop."
Castor - He convinced Teito to take the examination to enter the priesthood. The training he puts Teito through is vigorous and often involves his 'dolls' (which looks like Frau), life-sized puppets he controls with Zaiphon. Castor can sometimes be cold hearted as seen when he was willing to erase Teito's memories because their identites as the seven ghosts must be kept a secret.
Labrador - He gives Teito a flower of protection which later saves his life during an encounter with a Kor. He also gives Teito a drink made from sweet flowers to heal 'injuries to the heart'. In general, Teito often seeks Labrador for solace and advice. Having a somewhat odd trust in the lilic haired bishop, whom is extremely wise.
Hakuren Oak - Hakuren is Teito's roommate at the church. The two first meet after Mikage's death and Hakuren is walking by Teito in the church. Teito mistakes him for Mikage since they look similar to Mikage, but upon looking closer, realizes it wasn't him. the two had a bitter rivalry when they first met because Teito recignizes the name Oak meaning that he is related to Shuri Oak. Hakuren always annoys Teito's height by calling him an elementary school student, but this all changes when Hakuren witnesses Teito's slave brand, making him wonder, if although he always calls him a elementary school student, he may have never even been to one. The two then become good friends when Teito saves Hakuren from being attacked by a warsfeil in which Teito risked his life to save. Since the incident Hakuren offered Teito a handshake but Teito declines because what happened to Mikage, Teito then says that he will become his friend when he is strong enough to protect him. Eventually Teito and Hakuren have become very good friends and before parting ways to begin their apprenticeship after completing the exam. In the manga, Hakuren is seen trying to revive Teito's memory after it being wiped clean by Ayanami and being enslaved into the military as one of his Lieutenant.
Fia Kruez - He is the person in Teito's memory known as 'Father'. He took Teito into a church and raised him. When Teito was a child, he taught him many things, including the majority of the church's writings and old Ragg's language/writing. He also taught him much about the Eye of Mikhail. Fia Kruez loves Teito like his own son and acts like a father figure to him. later it is revealed that Fia Kruez is the younger brother of the King of Raggs, meaning that Teito's 'father is actually his blood related uncle. Fia Kruez was also the one who sealed Teito's memories in order to protect the Eye of Mikhail and hide the location of where he hid the Pandora's Box to save it from the Pope, which were sealed inside Teito's body. It is later revealed that he is one of the seven ghosts, Vertrag.
Mikhail - A angel that acts as the host of Teito's body, he possesses Teito's body through the Eye of Mikhail. When in control of Teito's body, Teito's irises become red and his pupils become slits. He is very fond of Teito, and is put out by the slave collar that limits his strength. Though extremely powerful, he tends to act like a petulant child and often makes undignified faces when talking with the Bishops, but can be extremely harsh and brutal, even merciless. Later in the series, the Eye of Mikhail is stolen. But Teito can temporarily pass a link through a spell causing a reaction.
Mikage - Mikage was Teito's best (and only) friend in the empire, while the people around discriminated him because of his background of being a sklave, Mikage did not even bother about the rumours. Their relationship as friends involves a lot of Mikage teasing Teito about his short stature, and Teito beating him up in retaliation. Even so, they are still very close, promising each other that they will die together and will always be "the best of friends". Their relationship is so close that Mikage even considers Teito his family and is unwilling to betray his friend when Ayanami took control of his soul. When Mikage died he felt so depressed to the point that he blamed himself, but Frau manages to comfort him by telling him that Mikage is already by his side. (As a reincarnation of a pink dragon named a Fyūlong). Even after Mikage's death, Teito still finds it hard to go on without his best friend, even stating that "When Mikage died... I felt like a part of me died as well". Mikage and Teito's friendship throughout the series is one of the main themes of the story. It is often seen that the spirit of Mikage guides Teito, and even lends him a gentle caress on the back or shoulder for support.
Ayanami - He is the man who killed Teito's 'Father' and seeks the Eye of Mikhail. Teito holds a great hatred towards Ayanami for killing Mikage right in front of his eyes and wishes to seek revenge against him which is what Ayanami wants. Ayanami is later to be revealed as Verloren, the death god that seeks Pandora's Box.
Ouka - Teito saved her from being attacked by a band of thugs, the two are similar in some ways in which both are hosts to the Eye gods(although Teito's Eye of Mikhail has been removed) and how they both have Fyulong dragons as their best friends (ouka considers her dragon Kururu like a sister while hakuren stated that Mikage was like a brother to him).Although Mikage's reincarnation is unable to speak the human language, Kururu does not wish to get along with him because of this. She admires Teito for his courage and agreed to visit the next God House with him, before they were attacked by Wars. At first, she mistook Teito as a God House member because of his clothes, but the issue was quickly cleared up. Teito gets the feeling that he knows know from somewhere. Ouka's real name is revealed to be Roseamanelle Ouka Barsburg.
Kurena - She is a servant who took care of Teito during his days as a slave, Teito said that once he enters the military he will free her. She has a scar on her neck as punishment for her carelessness under her previous master. To the present, she still keeps a picture of Teito and all the little things (sparkly stones, flowers, etc) that Teito had given her, which goes to show how much she still cherishes Teito. She is the only female character in the series so far who's truly important to Teito, as she is the closest thing he has to a mother.
Capella - He is rescued by Teito and Frau as they flee the Barsburg Church, and joins them in their journey to the 'Land of Seele'. Teito treats Capella like a younger brother figure and always takes care of him. Teito also taught him about learning Zaiphon. Capella gained the ability to use the healing style of Zaiphon after being told by Teito that they were going to the Fourth District in search of his mother. Teito was very happy that his Zaiphon ability was healing rather than offensive because he did not want him to follow the same path as himself in which Teito has stained his hands with blood during his time as a slave. We later find out Capella can also use offensive Zaiphon when his mother is threatened. Teito blocks the Zaiphon and tells Capella not to use it because it deals pain to the heart, but allows him to use the healing Zaiphon. Which sometimes he and Teito can be seen practicing with each other along the journey, before (in the manga) they find his mother and leave him in her care.
- His favorite food is macaroni gratin, his favorite drink is melon soda, and his favorite color is sky blue.
- His last name, "Klein," is the German and Dutch word for "small."
- Teito dye's his hair blond for the Hawkzile Race.
- His name "Wahrheit" means "truth" in German.
- Rumor has it that is supposed to be Eve's reincarnation.