Kairen

Kairen
Species	Demon
Relatives	Unknown
Affiliation	Himself
Status	Deceased
Debut	Toguro's Wish

Kairen was a Powerful Upper B Class Immortal Demon, of the same "species" as Younger Toguro, who could regenerate and was immortal. During the affair of creating a joint dojo for human psychics a little over fifty years before the show took place, Genkai and Toguro frequently attracted the ire of many a demon who sought to ruin the team, their dojo, and their students. However Toguro and Genkai were too strong. One of these demons did what the others failed to, and that was Kairen; he entered the dojo while the two were away and slew every trainee there. However, in the manga Toguro was defeated by Kairen and watched all his students slaughtered and was unable to do anything. Later, it was revealed that Kairen was trying to coax the team into entering a Dark Tournament, and he was essentially pulling the strings on Toguro as Toguro did to Yusuke, years later.

Kairen using his abilities to kill Toguro's students.

Kairen, in the dojo.

In the finals of that Dark Tournament, Toguro killed Kairen, but because of the pain he had felt for not being able to protect his students, he wished to become a demon like Kairen for his reward wish. The tournament committee granted this wish, and he became almost exactly like Kairen.

Trivia

• Kairen was labeled by Spirit World Intelligence as a Demon of the "Highest Class" which is odd, as the highest class of demon is S Class and Toguro, who killed Kairen, was ranked as Upper B Class, however at that time no A or S Class Demons were able to reach the human world and the knowledge of S Class is limited.