Osiris

"Oryx-Dead-King. Oryx-Dead-King. Three words, nine-word bursts over and over. Osiris?"

- Master Rahool

Osiris is an old Warlock who was exiled from The City. He has knowledge about the inner working of the Hive, as he knew about the Shrine of Oryx. He was also said to have "come too close" to understanding the Vex.

Exile
After his exile, Osiris then started a cult based on Mercury.

Trivia

 * There are three known members of the Osiris cult who still live: Osiris himself, Brother Vance, and Sister Faora.
 * Osiris was Ikora Rey's mentor.
 * Osiris is the only Vanguard Commander to have been exiled, and has been referred to as "the Zavala before Zavala".
 * Osiris' Ghost is named Sagira.