(First off: credit to users A Rising Wind and Powder2121 for basically inspiring this theory).
[b]What's up you glorious bastards!?[/b] Do you know how long its been since we've had some [b]real, [/b] [i]brand-spankin new[/i] lore to look at!? September! [b]Of last year[/b]! Boy let me tell you it is great to be back!
"What are you talking about?" Your probably not-insane mind must be asking. To which my totally-insane mind would reply: " [b]ONLY THE BIGGEST POTENTIAL BREAKTHROUGH IN EXO LORE WE'VE EVER SEEN![/b]" You're skeptical, I'm sure: after all, Rise of Iron hasn't even come out yet! How could we already have some groundbreaking lore reveal? Well, first off, let me say that this is just a theory, and it (as of now) has no backing in the lore; however, it is the fact that the lore doesn't [b]dispute[/b] this theory in any way that has me really riled up!
So here's the theory: we know Exo's minds come from human minds, yeah? Well, nothing in the lore says that an Exo [i]and the human its mind was cloned off of[/i] can't both be alive [i]at the same time[/i]. Due to Exo memory wipes, neither one would know they were basically just talking to themselves!
Where am I getting this? [b]Owl Sector[/b]! Well, more accurately, user A Rising Wind got some info on Cayde-6 from Owl Sector. Here's a link to his thread: [url=https://www.bungie.net/en/Forums/Post/213113457?sort=0&page=0]Patient E is Cayde[/url].
In this thread, ARW basically proves that Cayde was once an in-debt dude named Jun, who was experimented on by Clovis Bray to become one of the first Exos.
Here's where things get interesting: I have a picture of Jun. That's right: [i]human Cayde-6[/i]. How? Back in the early days of Destiny (I'm talking pre-Year One here) I purchased a book titled The Art of Destiny. To my knowledge, it is still available in the Bungie store, and is a great read. Anyway, the concept art in the book dates way back to when Destiny was just an idea: so far back, there is art from [i]before Exos had been added into the game[/i]. And it is within these pictures that I found the following beauty: [url=https://cdn3.vox-cdn.com/uploads/chorus_asset/file/2583142/Art_of_Destiny_122.0.jpg]Early Vanguard[/url]
That fellow on the right with the bomb rifle? He's labeled as "Jun: Human Hunter Vanguard." So I immediately assumed: this is human Cayde.
Then user Powder2121 had the [i]audacity[/i] to say that "No, that's Andal Brask." Many people also thought that, and I would have too had I not seen the picture labeled as "Jun." Then Powder2121 linked an image from the Arms and Armament book (from special edition Vanilla Destiny): [url=http://vignette4.wikia.nocookie.net/destinypedia/images/9/9a/Destiny_Andal_Brask.jpg/revision/latest/scale-to-width-down/198?cb=2015041617454]Look Familiar?[/url]
It should, because this is the same picture with a different name! (Cue X-files music).
Powder2121 then asked: "What if Brask and Cayde are the same person?" That's not possible of course, because [i]Jun[/i] and Cayde are already the same person, and Cayde personally knew Brask when he was alive! Unless....
Bear with me here: assume Jun and Andal Brask are the same person. People change names all the time in the Destiny universe, especially in the Books of Sorrow. Its kind of a theme at this point. Say the experiment on Jun just cloned his mind, and didn't kill Jun. Cayde-1 is born. Cayde-1 gets his memory wiped 6 times over the course of his lifetime. Jun changes his name to Andal Brask for some reason, and becomes the Hunter Vanguard. Cayde-6 and Andal Brask become friends, [i]neither knowing that they are essentially the same person[/i], due to Exo memory wipes. Brask can't have Cayde's memories, and Cayde can't have his due to the wipes.
There is nothing in the lore to refute this. As far as I am aware, this is entirely possible within the Destiny lore universe. I encourage you to try and refute or prove this theory.
Oh. And thanks for reading.
Edit #1: There has been [i]tons[/i] of arguing over the Andal/Jun thing. One user pointed out that his copy of the Art of Destiny says "Joden," not Jun. There is speculation about book version, book being used, etc. As for me, I do not currently have access to an Art of Destiny book, so if anyone wants to do some quality research, here's where to start.
Only one major problem. At first I thought there were two problems, as I happened to see the same comment thread where you got this idea. I think I might've replied to it also, but not positive. I was Going to say that in current lore his name is Andal Brask, not jun. Jun was an old name for him that got replaced when the game came out. But you cleared that up with the name change theory.
Of course that brings me to the problem. Exo's were created in the time shortly before the collapse. You could say it was technically golden age, but it was right at the end as exo's were created to combat the darkness. So If Jun/Andal Brask is cayde, that would mean he not only lived through a good portion of the golden age, lived through the collapse, was there at the founding of the last city and the guardian order, somehow acquired a ghost and became a guardian, rose to become a member of the vanguard (which takes time), and was still fairly young. Yes human life spans were increased in the golden age, I believe it said somewhere people were living hundreds of years, but not positive. Either way, this theory is impossible, as Jun/Andal Brask would have lived for over 700 years.