Possesses the Jagan and is an excellent swordsman. Hiei is one of the characters in the Yu Yu Hakusho franchise.
From a very young age he learned to care for himself, and only himself, but didn't completely close off his emotions as he is still able to care for others. Hiei is known as "Emiko", because he is a male fire demon born to an ice maiden, an all-female race. He was born male because his mother "interacted" with a male demon outside her isolationist Korime community, which led to him being cast out as an infant. After surviving his fall down, he was found and raised by a gang of bandits, but it didn't last long. After realizing the value of the Tear Stone shed by his mother at his birth, he wore the Stone in full view of everyone, hoping to attract enemies to kill. As he grew older, he killed mostly for fun, causing those that survived to greatly fear and reject him.
Later Hiei requested Shigure, the demon surgeon, to implant him with the Jagan eye. This only happened after Hiei succeeded in paying the doctor's asked price, telling him an interesting story. Hiei did when he told Shigure the story of his life up to that point in time, and was warned before of the physical cost of having the Jagan implanted in him. Despite the warnings that the surgery would drain Hiei of all his (former) strength and that it would be incredibly painful, he went through with it anyway. Afterwards, he chose to accept Shigure's lessons in the art of swordsmanship in order to survive. He did so because his original level of power, that of an A-Class demon, was reduced to that of a lower D-Class.
During his stay and training with the demon surgeon, Hiei decides to use his implant for what he originally wanted it for. To find the special jewel that he had lost in a battle with another demon, the very same one created from his mother's tears when he was a baby. He set out on his journey and instead of finding his jewel, Hiei found his way back to the Glacial Village where he was originally born in. Once there, he decided to find his mother, Hina, but would find her friend, Rui, the woman who was forced to cast him off the village and into a river below. From her, he found out that his mother had died years ago, she had committed suicide due to the depression of losing her son and witnessing his "death".
It was also here, from Rui, that Hiei learns of the existence of his twin sister, Yukina, who left the village without explanation a few years before. However, she also told Hiei that it was assumed by herself, and her fellow villagers, that Yukina reasons for leaving were more than likely due to discovering that she had a twin brother, and decided to seek him out. After she finished answering his questions, he simply turned to leave without another word. However, before he did, she quickly realized Hiei's identity as Hina's son, and begs him to kill her then and there for her part in his fate. After appearing to think it over, he refused and continued to walk away.
On his way back to Shigure, Hiei decides from then on to use his Jagan to watch over his sister, rather than finding his jewel. So it was, that upon his final departure from the demon surgeon, he decided to pay Shigure for his services as a swords-teacher. As payment for his teachings, Shigure has Hiei swear an oath to never to tell Yukina that he is her brother. Hiei accepts the terms, and states that he never planned to tell Yukina. After that moment, Hiei traveled everywhere, intent on finding his sister, Yukina. His search eventually took him to the Human Realm, and it was during this time that he first met the human form of Yoko Kurama, Shuichi Minamino. This took him from his quest briefly in the form of planned robbery of the Spirit World's artifact vault. Together with another demon named Gouki, the three stole three dangerous weapons from the Reikai, and became the targets of Yusuke Urameshi's first case.
Other than being a master swordsman, Hiei is also lightning fast, able to move much faster than human and sometimes demon eyes can follow. He is a master of the Kokuryuuha, or Dragon of the Darkness Flame, which he tamed and summons from the Demon Realm for his use through the mystical tattoo on his right arm. The tattoo was created when Hiei merged with the dragon in preparation for the finals of The Dark Tournament. It is actually a permanent burn that was scorched into his arm by the awesome power of the dragon.
He possesses an implanted third eye in the middle of his forehead, called a Jagan eye. Said implant amplifies all his natural powers, and enables him to summon both the hell-fires of his homeland, Demon Realm and the tamer, fires of Ningenkai (Human Realm). At the same time, it grants him several near psychic abilities, such as: Hypnosis, Telepathy, and Remote Viewing powers. Also, the Jagan allows Hiei to see quick movements, which was displayed when he saw that Kuwabara changed what sign he was using when he, Hiei, and Kurama played rock, paper, scissors to see who would fight next in a match in the Dark Tournament.
Yet, despite all this, Hiei must hide it behind a special sutra enscribed strip of cloth he uses as a bandana, because despite it being a part of him, the Jagan is a sentient being. Like the Dragon tattooed on his right arm, it has a mind of its own and needs to be kept in check by such items. Both the Jagan and the Dragon can overcome their "leashes", for their own reasons. The Eye does so only if it is in any way insulted; it did so during Hiei's early fight in the Dark Tournament, against another fire demon. The Dragon overcomes its "sleep" if it feels it is being misled, as it was when Hiei was being manipulated during the "Poltergeist Report" film. Either way, the sutra enscribed items lessen both sentient creatures' drain on Hiei's reserves of yoki, yet both are ready to be revealed when needed, whether he wants them to or not.
Hiei typically squabbles with Kazuma Kuwabara and keeps a cold and uncaring exterior, but seems to hold a certain amount of respect for all his teammates. He seems to be closer to Yusuke and Kurama. Hiei is grateful for Yusuke's trust in him when Yusuke sends Hiei to rescue the team from the Gate of Betrayal, and he places his faith in Yusuke during the Dark Tournament finals by allowing Yusuke to fight Toguro. Hiei also goes to great lengths to protect Kurama (almost destroying the medical tent during Kurama's match against Touya), and he relies on Kurama to heal him and help in fights (such as the fight against Dr. Ichigaki's Gatasubaru). Hiei prefers to work on his own agenda, and has a notorious reputation in the Demon Realm, but despite this, he is very honorable and always keeps his word. He does not tend to show his emotions, and doesn't always let his teammates know that he cares about them. Hiei can be kind and compassionate, but really doesn't know how to show such things because of where he grew up and the atmosphere there. From a very young age he learned to care for himself, and only himself, but didn't completely close off his emotions as he is still able to care for others. Hiei is known as "Emiko", because he is a male fire demon born to an ice maiden, an all-female race. He was born male because his mother "interacted" with a male demon outside her isolationist Korime community, which led to him being cast out as an infant. After surviving his fall down, he was found and raised by a gang of bandits, but it didn't last long. After realizing the value of the Tear Stone shed by his mother at his birth, he wore the Stone in full view of everyone, hoping to attract enemies to kill. As he grew older, he killed mostly for fun, causing those that survived to greatly fear and reject him.