It has risen to tremendous power in the underhive of Hive Taurinum, and at a time had a fellowship with the firebrands of the Redemptionist Crusade. This has long since been destroyed, as they had a dispute on the nature of the Emperor’s Immortality.
With their name being taken from the first time the Black Ships came to Argoth to reap the bounties of the planet, in an almost mythological past, they too harvest the unfaithful delivering them to the cleansing fires of the God-Emperor, whose Grace would have saved the wretch, if he had stayed true.
Led by the charismatic Aren Dathrin, they have gone from strength to strength and at this point, they have a large following with at least 500 ministers of faith.
They believe that the current situation on Argoth is a direct product of the sinful lives led by the population of the hive, and the only way to cure the cancer that is eating at the very souls of the hive, is to cut it out and purge it in holy flames.
The version of the Imperial Creed that is worshipped by the Reapers, is in fact a perverted and distorted version. In reality the faith of the Reapers has been poisoned by a Daemon of Slaan’esh, and they style him as the God-Emperor of Mankind in a twisted version of a grinning man sitting in the Golden Throne.
The pyres of the cult serve as a medium to inflict the most pain upon a victim, and the confessions that the order seeks is a mockery of Imperial custom, again only serving the Prince of Pleasure.
The debased faith of the Reapers was cleansed by the Kill-team after their first insertion on Argoth, although there might be remnants of the sect in the Underhive.