The tale of the famed Warlock Osiris is one that many Destiny players can appreciate: a story of obsession.
Osiris was a veteran of the Battle of the Six Fronts. His prowess eventually lead to his appointment as the Tower Vanguard, at the recommendation of the legendary Titan, Saint-14.
Unfortunately, Osiris quickly became bored in this position. He began to explore The Darkness, trying to discover its nature. Here, he discovered an infatuation with The Vex. He was intrigued with their power.
His boredom with menial tasks and curiosity with the enemies of humanity led The Speaker to take him on as a pupil. The Speaker soon found that Osiris' questions went beyond the curiosity of the average Guardian.
Osiris theorized that much of Guardians' memories had been fabricated by their Ghosts and their "knight-errant" mentality was the result of manipulation of The Traveler. Further, he believed it possible that The Traveler had manufactured Guardians as nothing more than living weapons.
The Concordat faction claimed to have found records that Osiris was a Golden-Age experiment that was "mis-incarnated as a human by an inept Ghost." While The Speaker rejected these concerns, he was very concerned with the direction his pupil's mind wandered.
The Speaker found his questions "divisive and disloyal," and as faction tensions reared to new heights, felt that he could break the City's unity. With The Traveler as humanity's sole common hope, Osiris' questions came at an inopportune time.
Then, it got worse. The Traveler said of him in the Grimoire Card, 'Osiris':
"And then it got worse, dabbling in thanatonautics, Ahamkara-lore, chasing after Xur and the tricks of the Nine. Launching expeditions into the Reef and beyond at a time when ships were irreplaceable. Your quest split Guardians along ideological lines. This was your greatest crime: Hunters chose to pursue your visions instead of protecting refugees, Titans assembled teams to chase the legendary Vault of Glass instead of striking the Fallen, and Warlocks turned away from the study of the Traveler in favor of your ultimate obsession... learning the exact nature of the Darkness.
When debate became argument, and argument became acrimony, I realized you had already become a cult of personality, attracting Guardians who wanted a clear idea of why they were fighting, what they faced, and how they would ultimately win."
Osiris eventually left The City. He wandered through Vex structures, hoping to find truth outside the walls of academia and free of the walls of The Tower.
Ghost searched for him, to no avail. Some returned claiming him dead, and others describing him as discovering "answers from the far reaches of space and time." He had apparently navigated the Vex's gate networks, exploring them for answers.
Here, he devised multiple theories: That The Vex were incapable of simulating Guardians; that The Traveler was incubating a sleeping god; that The Traveler was an 'ontoformer.'
(The prefix 'onto-' means 'to be' and '-former' is 'to make.' The most likely interpretation is that an ontoformer can bring things into existence, in defiance of the Laws of Thermodynamics.)
So, where is he now? That remained a mystery. The legendary Titan Saint-14, himself, searched for him. Tragically, he never returned from this hunt and was declared dead by The Tower.
The Speaker mourns the loss of Osiris, "Perhaps you are still out there. If this reaches you, I would very much like to speak with you, to hear your theories in your own words. Perhaps what drives a Warlock to madness is truth."
With Guardians such as Toland, Osiris, Saint-14 and Praedyth having been lost to curiosity of the Dark forces at our gate, perhaps the Speaker was justified to hold Osiris back. So many Guardians have been lost to the deepest corners of their own discoveries.
Osiris, though, may still be alive. The trailer for 'The Curse of Osiris,' has us follow his path. Perhaps we will find him.
Theories vary in describing what we may find, but the sheer persistence of The Cult of Osiris in finding Guardians worthy of his mark is certainly a compelling testament to the legend left in his name.