Kyou Shigoku

Kyou Shigoku (至極京 Shigoku Kyō) is the main antagonist of Juujika no Rokunin, being the primary catalyst for many events in the series, as well as being the archenemy of Shun Uruma.

He is the leader of Uruma's group of bullies who tormented him in his childhood, Kyou sets himself apart as completely apathetic, cruel, and psychopathic compared to the other four.

After Uruma had murdered all of Kyou's followers, the former decided to take his revenge on Kyou. However, it was later revealed that Kyou has a large group of followers, particularly the "researchers" (one of them being Jun) who are sent by Kyou to deal with Uruman.

Appearance
Kyou has an overall androgynous appearance with neck-length black hair and bangs that reach to his eyes. Uruma noted that his eyes are barren and completely void of any emotion.

Personality
Shigoku Kyou is by all definition, pure evil, a complete sociopath with no regard for anyone nor anything, seeing all people as mere test subjects he can experiment and manipulate with until he's satisfied or bored with them. These traits have shown at a young age where he attempted to bully and torment Uruma to see how much him and his gang could make him suffer before he committed suicide. He even was perfectly willing to kill him at the time.

Kyou presents himself as calm and logical while also being incredibly cruel, twisted in nature, and sadistic, as evident by his disturbing fascination with the concepts of life and death. His belief is that the greatest action a human can perform is killing another human, and his primary goal being to kill an individual (whether directly by his own hands or indirectly through somebody else) for absolutely no reason whatsoever.

While he is charismatic and capable of leading the other boys, Kyou has expressed no emotional concern or attachment towards the other four bullies; he didn't hesitate to push Hiro Madoka (someone he's known since elementary school) down a cliff and in the path of an incoming car, something that could've potentially killed him. He also casually gashed Kuga with a pen after the latter pinned him down, permanently scarring him.

After the deaths of the other bullies at Uruma's hands, Kyou showed no visible sadness or concern, even at the thought that they were potentially next; rather he was interested in seeing how that series of events would play out.

Notably, while Uruma was "exorcising the demon" out of Hiro, he called Kyou "the worst demon of them all".

Unlike the other four bullies, Kyou is far smarter and physically stronger than he appears to be. For example, it was mentioned that he was a prodigy at a local school and that he won a black belt in Judo, making him one of the most powerful people in the story. Later on, it's revealed that he also has a group of supporters who may or may not be just as bad as him, showcasing a highly manipulative and charismatic aspect of him akin to that of a cult leader, able to make ordinary people succumb to their worst impulses and follow him blindly and loyally. This shows that Kyou is already far worse as a threat than he appears to be.