A Guardian, who was the Warlock Vanguard before Ikora Rey whose divisive beliefs led him to leave the City in exile. Osiris was present the Titans at the Battle of Six Fronts after which Saint-14recommended that Osiris be appointed as Warlock Vanguard. While Vanguard, Osiris grew tired of his role and began to question the motives of the Traveler. The Speaker views this as a crime. He became fascinated by the nature of the Darkness, and he pursued a number of controversial avenues to further his understanding, including Ahamkara-lore and thanatonautics. He was especially interested in understanding Oryx and the Vex. The Speaker believed that the tedious strike missions and instead encouraged guardians to explore the nature of the darkness and strike places like Crota's nightmare world or The Vault of Glass. This has led to guardians abandoning their posts in search of these things. He dabbled in thanatonautics and asking blasphemous questions about the traveler. He asked if our memories were prefabricated by the traveler and sent guardians chasing after the Ahamkara and chasing the Nine. Because of the toxic philosophy that Osiris put forth, he was exiled. Osiris quickly became a popular figure to those Guardians that had grown weary of dutifully carrying out the orders of the Vanguard. His questioning of the Traveler was considered disloyal, and the sway that he held over Guardians was considered dangerous. He left the City in exile, although whether this was by his own accord or by the will of the Consensus is not clear. A charismatic leader, Osiris left behind a number of adherents who remain loyal to him. His study of the Vex led him to set up a number of camps across Mercury, the best known of which is The Lighthouse. The Lighthouse: I presume the lighthouse was a home of the cult of Osiris before they were chased off by some (vex possibly) uncanny being or possibly eradicated. Either way if you go to the lighthouse there is a room some people have dubbed "Xur's House" but there is a human skeleton and a vex there with a gaping hole next to it that reminded me of a portal of some sort. The fact that that room is so secret means that someone stowed away in the lighthouse and might have been caught after the departure of the cult, leading to his demise. Seeing that he is the only dead body their as of now and it is in that room further supports that he was the only person there at the time of the attack. The others however must have vacated in a hurry as there is still a ship there ready for take off. There are possible shops still set up and even candles still lit all over the place. Whatever caused them to vacate made them run FAST After the release of Skolas, two Guardians visited the Queen of the Reef, and asked for aid in defeating Oryx. It is believed that these Guardians were Eris Morn and Osiris, but this has not been confirmed. One of Osiris' disciples, Brother Vance, is stationed in the Vestian Outpost in the Reef, and grants Guardians passage to the Trials of Osiris, a tournament that pits two teams of three Guardians against each other in a fight to the death. Success in the Trials grants an invitation to The Lighthouse. Sister Faora isn't mentioned much but she does prove a point in her existence that the cult of Osiris expands much further than we imagine and thanks to Osiris himself possibly across multiple timelines