The HIve (Second Human Empire name: Unknown, translated Shadow's Legion) are an ancient macabre species from the Duiz'zui Universe that worship and serve an entity known as the Darkness. They also follow the teachings of the Deep, specifically a principle known as the Sword Logic. In the Dui'zui Sol system where they have built the Hellmouth and Scarlet Keep, as well as having a presence on certain regions of Earth, around Saturn, where the massive Dreadnaught orbits, the icy regions of Mars and on Titan, where they infest the ruined arcologies.
The Hive are an "impossibly ancient" race born from a pact with the Worm Gods. Hive structures delve deep into wherever they lay claim to, unheeding of the damage done in the process, crafting linked caverns and gothicesque columns; these underground spaces resemble a dungeon recently pulled up after an extended period underwater. They are able to manipulate the physical world in ways humanity can only begin to imagine, and have witnessed the Darkness consume countless worlds in the past.
The Hive appear to have been somewhat aware of the existence of the other realties and begun to spread to other realities to spread the influence of the The Darkness to other worlds, slowly becoming a threat to the Alliance of Nations and to the Axis of Empires during the Day the Multiverse Burned and the Second Necromorph War. With their many sects across several universes, the Alliance would sent the Guardians, Jedi, Tenno and high class mages to provide aid alongside highly trained military forces to handle the Hive threat after the Klendathu Massacre and other worlds they attacked.
The Hive have some sort of mixed relations to few races, some be allies or enemies such as the chaos, taking advantage over the Chaos Gods and other entities with their connections to the material realities at times, developing a strong rivalry with the Chaos unless made temporary pacts, alongside with the Cryx is yet uncertain. Oryx, the Taken King would use his powers to subjugate those as his Taken after launching his attack in the Eai'eei Universe during the Falmart Campaign.