The House of Oni was a Fallen house that arose during the SIVA crisis, they are a smaller house however are still large enough to destroy the city as a whole, with a fleet of around 13 Ketches. Most members of this House consist of former Devils that did not believe SIVA was all-powerful, and still saught the great machine- while another number of the house are of the House of Exile, or were. Their kell is known as Heraksis and their Prime Servitor is known as Grekiks-Prime.
The House of Oni are of course a split-off faction of the house of Devils, hence many ideals carry over- the only difference is that House Oni do not believe SIVA to be a valuable asset, but rather another tool of the A.I Warmind: Rasputin to destroy them. They do not have Dregs, as all Dregs who're enlisted into the House are relieved of their docking caps- making these Fallen a much more dangerous house- as Ether is not restricted to the Kell and Captains..but all members.