EDIT: This theory has been SHUT DOWN. I forgot one crucial detail: when the Vex erase someone from existence, NO ONE from ANY TIMELINE remembers them. Everyone go home, put your tin foil hats in the garbage on the way out... So after reading some Grimoire cards along with the Book of Sorrows, as well as doing a recent replay of Regicide, I have come to a conclusion regarding Nokris, and a surprising potential discovery about Oryx. 1. Theory of the Fate of Nokris and the Calcified Fragments [spoiler]I still don't know who Nokris is, but he must be related to Oryx and Crota in some way. Here's what I think happened: When Crota accidentally released the Vex, there is a very good chance that Nokris was there to help defend the Osmium Throne/Dreadnaught. Even though Crota and Oryx obviously survived the Vex, Nokris may have been erased from existence. And then, even though the Vex were defeated, Quria may have at the last second teleported Crota and Oryx to a different timeline - [b][u]OUR TIMELINE[/u][/b] In our timeline, Nokris never existed, with evidence being that there is no information about him in the World's Grave or the [u]Calcified Fragments,[/u] which is my next point. Perhaps in the timeline that Crota and Oryx came from, the Books of Sorrow did detail Nokris, but since he doesn't exist here, the Fragments must not be the originals at all, but instead, our timeline's versions of them, wherein again, Nokris never existed.[/spoiler] 2. Theory on the Cathedral of Dusk Crucible map [spoiler]Oryx was saddened most likely by seeing this. No Hive understands Vex Gate technology, so Oryx couldn't find a way back. But he didn't want to just forget about Nokris because he must have been important. So he built 2 monuments dedicated to his memory: 1. The Nokris statue outside the Altar of Oryx. This one is obvious enough, no explanation needed. 2. The "Cathedral of Dusk." That's right, the Crucible map we all know and hate. If you read the Grimoire behind the lore of the map, the Vanguard and the Warlock Orders can only speculate its importance. The most logical explanation of it is that it's a grave marker to some Hive entity. Which in this case, it sort of is. Sort of like a massive monument to a dead - or perhaps nonexistent - military commander. That was Oryx's reason for the creation of that place: so that at least he himself would never forget Nokris.[/spoiler] 3. Theory on Crota and Oryx being from a different timeline [spoiler]This then leads on to the discovery: if all of this is true, then that means that the Crota and Oryx we fought were from the other timeline, not our own. So that would mean that when they were cast out here, there very well could have been 2 Crota's, and 2 Oryx's; 1 of each from this timeline, and the 2 we know and we killed. Most likely, the Crota and Oryx from our timeline thought of these "doubles" as impersonators attempting to steal the throne in Hive fashion. We can only assume that in the end, Crota and Oryx from the other timeline won.[/spoiler] 4. Small conclusion [spoiler]If Oryx went through all that trouble just so that Nokris would remain relevant, it can only mean one thing: Nokris must have been powerful, on par at least with that of Crota, or higher. Besides Oryx and Crota, the only other entities that may know of Nokris's existence are: 1. Any Vex that may have survived the failed attack on the Osmium Throne. 2. Atheon, Time's Conflux, because Atheon controls all of time, and all timelines from the past to the present to the future. So obviously he must know something.[/spoiler] So yeah, that's just my spinfoil hat theory. Please leave feedback and feel free to discuss. I just made this up today, so more research will be needed. 😂