Samurai Deeper Kyo ... One of the best Manga ever!

Samurai Deeper Kyo (サムライ ディーパー キョウ, Samurai Dīpā Kyō?) is a manga series written and illustrated by Akimine Kamijyo. The manga was serialized from October 15, 1999 to May 10, 2006 in Kodansha's Weekly Shōnen Magazine, and collected over 38 volumes.

Samurai Deeper Kyo follows the story of Demon Eyes Kyo (鬼目の狂, Oni Me no Kyō?) as he seeks to regain his body after his soul was sealed inside the body of his rival, Mibu Kyoshiro. Kyo is joined in his search by the bounty-hunter Shiina Yuya, the heir to the Tokugawa shogunate Benitora, and Sanada Yukimura, a known rival of the Tokugawa.

Underlying the principle story arc of Kyo's search to reclaim his body, there are many smaller arcs, each leading to the next one. The basis of many later revelations are established many volumes in advance. In the manga, it is revealed that all of the Mibu, except for Kyo , are descendants of "Battle Dolls", creatures created by the Mibu to fight for their amusement. In time, the Battle Dolls come to believe they were the real Mibu, and that the real Mibu were destroyed by infighting. The extant Mibu are gradually being killed by the "Disease of Death". Muramasa's sister was the first to be killed by the Mibu Disease, but others soon followed. The disease manifests itself when the infected person reaches a certain age. For this reason, the aging process has been stopped in Antera, Tokito, and probably others.

Demon Eyes Kyo (鬼目の狂, Oni Me no Kyō?)
He is known for his demonic blood-red eyes and is one of the most feared samurai in the world. He carries a legendary nodachi called Tenro (Heavenly Wolf), made by mastersmith Muramasa. In the manga, he is depicted as a cold, unbeatable samurai. When he was young, he was shunned by all of the Mibu clan for his demonic red eyes except for the Sendai Aka no Ou (Former Crimson King). After killing Oda Nobunaga, he was thrown into the Mibu dungeons until Muramasa rescued him and trained him in Mumyo Jinpu Ryuu. Kyo is the last remaining True Mibu. Sendai Aka no Ou asked Kyo to seek out the outside world and one day stop the former King himself if he was to become evil and destroy the world.

Mibu Kyoshiro (壬生京四郎, Mibu Kyoshiro?)

A remarkable swordsman, depicted as the only rival to Demon Eyes Kyo. He wielded the Shibien (Purple Sword), a Muramasa. In the manga, he is depicted as one of the heirs to the Aka no Ou throne, the Red Eyes were proof of his Mibu lineage. He is a "Red Cross Knight", created from the flesh of the Sendai Aka no Ou. Though he is able to control the Red Eyes, he is not a true Mibu, but merely a more powerful battle doll resembling the first generation of battle dolls created. It is depicted that he is stronger than Demon Eyes Kyo, although they are trapped in a same body.