Shinriyoku

Overview
The Shinriyoku (Shin - Ree - Oku), also known as the Anti-Devil Society, is a guild of mages composed of Devil-Slayers and other mages who advocate for the extermination of devils, in order to benefit both mortals and the other races of magical beings.

They are the main villains of Book 5, Highschool Project: Necromance of Black, with a main focus on Itsuki, Diana, Escalus and Beast.

History
First founded three years before the events of Book 1, the Shinriyoku first came together after being gathered by Diana, who went by the name of Glacies, and Itsuki Echo, who had a bad taste for devils, as they were the ones who had slaughtered his family.

Together, they gathered seven other Devil-Slayers, including Escalus, who was appointed the leader of the Shinriyoku, which also went by the Anti-Devil Society in the Underworld's files, for the sake of convenience. Later, they met the powerful SX-Class Mage named Tozen Yoko, a Beast-Slayer, who joined their ranks to affiliate himself with their goals.

In Book 5, where they play the role of the main villains, they slaughter half of the entire devil population, carrying the same ideology as the late White God-Slayer, who thought that exterminating the devil race would benefit both mortals and other magical races.

Trivia

 * Asami's last name, Akatsuki, is taken from the villain group seen in the anime franchise Naruto Shippuden


 * Yazetsu's last name, Espada, is taken from the villain group seen in the anime franchise Bleach
 * Diana's other name, Glacies, translates from Latin into "ice"
 * Yohan is inspired by Avatar Aang from the popular animated franchise, Avatar the Last Airbender, whose primary element is also air, fighting with a staff to assist them
 * Kikio is inspired by Kama from the anime franchise Fairy Tail


 * It's said that the Shinriyoku contain at least one-third of all Devil-Slayers in Dimension-173
 * Diana is the strongest member of the Shinriyoku, being ranked at SZ-Class, with Beast at second place, being ranked at SX-Class. With their ascended magical forms, Escalus and Itsuki follow closely, being tied for third place. The weakest member, as stated by Zane, is Ryuji, and the deadliest one in a long-term battle, as stated by Amber, is Mayako
 * Escalus's last name, Genki, is taken from the Genki Dama technique seen in the popular anime franchise Dragon Ball Z; similarly, they both unite things, whether it be people or the energy from people.