Ōtsutsuki Cult

This was a congregation founded and led by Boro from Kara, who over years recruited and manipulated people from all over to join under him as a Saviour spreading the praise of the Ōtsutsuki clan as Gods who will save the world and unite them under the Infinite Tsukuyomi.

Overview
According to cultists, during the Fourth Shinobi World War, Boro experienced the miracle of the Infinite Tsukuyomi, leading him to viewing it as a jutsu meant to save people. Making his way to a land, Boro formed a congregation, with its headquarters constructed so Boro could welcome the gods. The structure had a chapel and an auditorium, where Boro gave enlightening sermons. Using a machine in a secret room within the lower levels of the headquarters, Boro created viruses, so he could save people with the vaccine he created. The room also contained a Space-Time Gate.

Boro would spread his virus under the guise of a plague in towns and villages, before making his presence publicly known and curing them. Many of the believers who joined him had ran away from their homes, and thought of each other as family, as well as viewing Boro as responsible for everything they now had. He taught his congregation that salvation could be achieved through the Infinite Tsukuyomi, framed the Five Great Shinobi Countries as evil for murdering several of those Gods, and that he received an indestructible body from a 'God" he met.

With the goal of gathering potential vessels for Isshiki Ōtsutsuki, Boro chose Kagari and many other believers to be test subjects for experiments under the deception that they will be in service over three years and meet directly with the gods. After leaving, the congregation lost contact with them all over time. A file documented the data from the experiments, with it listing all the subjects as deceased.

Despite being ordered by Jigen to dispose of several cyborgs under the service of Kara, Boro instead hid several including Ada and Daemon in a base in the snow, being guarded by Bug. After Boro's death, Konoha sent Konohamaru and Sai to investigate the main branch of the cult in hopes of extracting more information on Kara. There, they revealed Boro's death to the cultists, his deception and experimentation of the viruses on unwitting members. However, the members were so deeply brainwashed that they denied any wrongdoing of their "saviour", and even when Delta arrived to destroy the entire main base of the organisation to disconnect any links back to Kara, they remained in the collapsing building, believing that Boro would save them as they perished. The facility was almost entirely destroyed, and those who survived were left traumatised and mentally broken by the revelations.