ALL CREDIT FOR THIS LORE POST GOES TO u/BringItForth
I originally developed this theory before The Taken King was released, but it was quite incomplete and is not required reading to understand what is presented here. The additional material released in TTK leads me to believe that the basis of the original theory was correct, but has filled in some holes and made other things nearly certain. For the sake of uniformity and readability, I have presented links to The Ishtar Collective in case you feel the need to read the cards yourself. This is quite a long post, but I know that doesn't deter people here. Thank you in advance for the time you spend reading this.
The Exo Stranger, like many Destiny characters, is shrouded in mystery. What do we know about her? She does not have a Ghost, though she does recognize what they are. She has a seemingly begrudging tone when she says that she “was not forged in Light.” She also says that a side must always be chosen, and then sounds as though she is remembering something sad when she adds, “even if it‘s the wrong side.” She also refers to it as “your Traveler” as opposed to just “the Traveler.” It is also made clear that she views the Vex as the greatest enemy. She also claims that the Vex are the reason we have both been brought to our current location.
When asked for direct assistance with the problem at hand, she declines and insists that her path is her own. She does however state that “Where our paths cross, ground could break.” What could one person possibly be doing that they believe to be more important than helping us save the Last City on Earth?
Finally, she seems to be communicating with at least one other individual who knows who she is. To this person she gives the orders, presumably to someone in a ship “Hold position, kill the engines and don’t let them find you.” She is then transported away in a manner that appears somewhat similar to transmat, and it seems she is returning to a ship.
Speaking of transmat, there is a rare jumpship in the vanilla game known as Eon Trespass that was “born from the mind of Elsie Bray, 3 years before she disappeared.” The name, “Eon Trespass” implies that the ship was designed to break the rules or boundaries of time. This is the only reference to Elsie Bray by name anywhere in the game or the Grimoire. Who else do we know that has a ship and likes to disappear?
It would also appear that the FWC in our current time is aware of the Exo Stranger. Lakshmi-2 stands physically above everyone else in the Tower, as if to observe them, and has some very interesting dialogue (all from the vanilla game):
”I can tell by the way you stare at me that you’ve seen her, haven’t you?” Lakshmi is a female Exo, so the only other named character her appearance might remind us of is the Exo Stranger.
“You think the Guardians can carry the fight alone?” This implies that she believes we need the help of people who are not Guardians. The Stranger has told us she is not a Guardian (“not forged in Light”)
“A trillion timelines, and all at war. Like a thousand red flowers growing in a black garden.” The Stranger's main objective in the vanilla game was to lead us on the correct path to the Black Garden to destroy a manifestation of the Darkness at its center. This line also implies that Lakshmi knows that Black Garden exists outside of time, and that there are multiple timelines existing at the same time.
“What if there were a single timeline untouched by war, would you have any idea how to live in it?” Take note of the fact that she does not ask us to imagine a timeline without the Darkness, but a timeline without war.
“She will find it Guardian, and when she does, we’ll be there.” This implies that Lakshmi knows the Stranger is actively searching for a specific timeline. How could she know this unless she were working directly with the Stranger?
The Ghost Fragment for the Future War Cult reveals that they have access to a time machine of sorts. Entering the Device allows the subject's mind to experience alternate timelines. With the release of TTK, this was explicitly stated to be the function of the Device, and it is explicitly stated to be based on Vex technology encountered by the Ishtar Collective. It was used only under the supervision of a warmind and in combination with a drug designed to essentially keep the Vex out of one's mind. A Vex Vax. It becomes apparent through testing (both by Sundaresh and later the FWC) that the process is physically dangerous for humans to experience. At the end of the card, it is heavily implied that this is indeed the same Device used by the FWC, as Sundaresh established the first test record and labels it:“..RECORD 0-CHASM-01...” and closes the card with “I can’t take this journal out with me, so I’ve left it for the others, and asked them to continue the log. Maybe it’ll become a tradition. The gospel of our little cult.”
From the Ghost Fragment Future War Cult:
“RECORD 343-CHASM-7891...The human mind is too weak for it. Too weak to look into the Future, or to understand what it sees.”
There is, however, a single record of a test subject who was very grateful for the experience and felt it had improved her-
"Subject twenty-three entered the Device at 11:00. A clever girl from the Core District; an artist, before she joined the War Cult.
At 11:03 she reported a sensation of floating. At 11:06, a sensation of lights within the darkness of the Device. Between 11:06 and 11:32 she reported these lights variously as white, golden, and blood-red. At 11:32 she reported a sensation of someone taking her hand; a stranger, but also herself. Twelve subjects have reported similar experiences. At 11:33 she reported the sensation we have called "The Opening Of The Veil." The Device recorded temporal displacement of her consciousness to the order of six degrees. At seven she began screaming. Brainscans near-death. Removed from the Device at 11:34.
She believes without question that the Device granted her a vision of the future, and that it was one of utter Darkness. She thanked me for this enlightenment. She says it will make her stronger.”
The end of this card raises a few questions; why would an “artist” need to be stronger? What did she mean by “enlightenment”? Why was she so grateful for these things that so nearly killed her?
Next, let's take note of the description given of the interior of the device, which again is based on Vex technology. Where else in the game have we seen white, golden, and red lights coupled with Vex technology? The Oracles in the Vault of Glass. They appear in all three colors at various points throughout the raid. What do the Oracles do? They determine reality and set things adrift in time. You may have also noticed that the FWC logo is white lettering with gold and red edging against a dark blue background.
With the release of the Taken King, the Stranger and the FWC are explicitly shown to be working together. The new Ghost Fragment Exo Stranger 2 sees the Stranger keeping records in the same manner as Maya once did, the way the FWC continued to do throughout their history. However, the Stranger's records contain one important difference:
“RECORD 167 - BRIDGE – 5.2 -
Successfully observed Guardian discovery of Hive on Luna. No evidence today of knowledge past Vex breaches here. Delay in return command is a liability to solve before engaging this close again.”
Her records contain the word BRIDGE (“how do you step ACROSS?”) where FWC records contain the word CHASM. I believe this confirms that FWC records are mere glimpses of timelines, whereas the Stranger is able to use their device to actually physically join timelines, albeit temporarily. I also believe it establishes that the Stranger and the FWC are using the same device, and further solidifies the widely popular theory that they are working together.
Also a part of TTK, the quest called “Not Forged in Light”, a direct reference to the Stranger, sees Lakshmi-2 guiding us through the Vault of Glass, Twilight Gap, and the Black Garden, and at the end we receive an exotic version of the Stranger's Rifle. During this quest, we first receive a signal from Praedyth who has been cast adrift in time in the Vault of Glass. We eventually recover his Ghost with FWC markings on it.
From its file numbered 00003:
“Every timeline I see through the door of my cell, every sliver of reality, bears one constant. Her. She is always there. Standing sometimes off to the side, sometimes in the foreground. Sometimes sad, sometimes speaking to herself. And always carrying a gun.”
This again confirms that the Stranger is indeed present in multiple timelines. It also establishes another point of contact between her and the Vex (“they brought us here”), as well as her knowledge of their use of a network of gates to regulate timelines and realities. We discover a physical remnant of Praedyth, his Ghost.
Praedyth also states in one of his transmissions that the Vex believe the Taken to be one possible end of their final timeline (evil so dark it despises other evil), and that perhaps this is why he has finally been able to send a signal through time; so that we as Guardians might be coerced into acting in the Vex' best interest temporarily, thus preserving the possibility that the Vex might eventually triumph.
After searching for Praedyth, we are sent to Twilight Gap to investigate what Lakshmi-2 refers to as “a...ripple. A snag in the timestream”. While there, we are constantly beset by the Shadow of Oryx which causes our vision to slowly fade to black, much like being Marked for Negation in the Vault of Glass. Also like the Vault, we are able to lift this effect by Cleansing ourselves in pools of Light. Eventually, we open a chest and discover a bracelet upon which Lakshmi-2 recognizes the personal sigil of Ana Bray. On the Hunter cloak Strength of the Pack sold by the Speaker, the description reads, “A pattern worn by Ana Bray during the fateful battle of the Twilight Gap.” This line, the only reference to Ana Bray in the vanilla game, implies that she did not survive the battle. The final reward for the quest is presented with text that reads in part, “Death, again. Like Ana Bray, a Guardian fallen to the second death.” “Second death” in this case means that Ana's Ghost was extinguished, preventing her from being resurrected again. This confirms that Ana Bray is permanently dead. This is the second time Ana is mentioned in the entire game, and it's in a quest for the FWC named after a direct quote from the Exo Stranger. Why would Lakshmi recognize Ana Bray's personal sigil? Perhaps she knows someone in Ana's family that was close to her?
We also learned in TTK that Rasputin has encountered the Stranger, and does not recognize her.
From Ghost Fragment Rasputin 4:
"You stand here now and now and now many times,”
a direct reference to Ghost Fragment 'The Exo Stranger',
and here I am awonder, all awonder, how you manage it. How do you step forward. How do you step back. Do you step ACROSS is there a world of worlds, a web, and you a spider upon it. Are you searching for that one thread you need? Is that thread named victory?
You’re not one of THEM
[long dead, alive again, their bodies grafted to powers they and I do not understand]”
Here Rasputin establishes that the Stranger is present in multiple timelines. He wants to know how she is accomplishing this. He also notes that she is not a Guardian - “long dead, alive again”
[the flower eater, the queen of final shapes, that which also inhabits its petitioners]"Here he notes that she is also not a minion of the Darkness.
and you’re certainly not MINE although once you must have been"
This is Rasputin inferring that he was present for and likely instrumental in the creation of the Exo race, a very long time ago. We also know that there was a warmind (whose name is never given) present during the events of the Vex grimoire cards, including Vex 5, which establishes specific contact between Maya and a warmind. This is important because it means that Rasputin would likely recognize the Exo Stranger if she were Maya Sundaresh, as he access to all files from all warminds. Beyond that, he now has access to the Ishtar Archives (thanks to us) which would feature Maya heavily.
The last part of the original theory comes in here. Though perhaps only a coincidence, the original FWC jumpship The Teilhard War has the same basic configuration as the aforementioned Eon Trespass, but with FWC colors and branding. This brings us back to Elsie Bray.
I propose that The Exo Stranger is Elsie Bray.
I believe Elsie and Ana are sisters, and possibly the final remaining members of the Bray family. Elsie Bray was human and was not chosen to be a Guardian. Ana Bray was. As a Guardian, Ana was present at the battle of Twilight Gap, and though the City triumphed, she did not survive and neither did her Ghost. Elsie was devastated by the loss of her only sister, and blamed the Traveler, feeling that had Ana not been a Guardian, she would still be alive. She mourns for years.
Elsie lived in the Core District of the Last City, working as a jumpship designer (or “an artist” if read as one of “Lakshmi's mocking hints”). At some point, she hears that the FWC is looking for recruits. Desperate to find any way to see her sister again and intrigued by the word “future” in the Cult's name, she decides to join the Cult and volunteers to be a test subject in the device. She is designated Test Subject Number 23.
She is shown a vision of the Vault of Glass and the Oracles within as well as a demonstration of their power. She then encounters a person in this vision who takes her hand. She recognizes this person, despite never having met them. I believe that this is because Elsie is a human, and she is recognizing her future self as an Exo in this vision (a stranger, but also herself). After thanking Lakshmi for her experience within the device, and realizing she must be “stronger”. Elsie decides to find a way to become an Exo.
Elsie knows that she will need a ship to find an old Exo body that works (or can be repaired) well enough to have a consciousness loaded into it. She then built this ship (a fairly quick process in the Tower) and named it Eon Trespass as it would carry her on her journey to break the rules of time. After three years of travel, she had all or most of a functioning yet “empty” Exo frame, and thus returned to the FWC ready to beg Lakshmi-2 if that was what it took.
As it turns out, the FWC were already looking for an Exo to use the device, as it is more tolerable for Exo minds. Additionally we must assume that Lakshmi-2 (named after the Hindu goddess of love) has some reason not to use the device herself, why else would she be in the Tower looking for recruits? It also appears that she would be very sympathetic to the plight of lost loved ones, “as if the secrets she guards have taught her to cherish every moment.” Perhaps this woman standing before her reminded her of herself before she became an Exo. Elsie begins to share her story with Lakshmi, detailing the loss of her sister, her inability to change it, and the helplessness she has felt since losing her. As she listens to her plight, Lakshmi realizes that Elsie is the perfect candidate to use the Device:
She has personal motivation (like the Stranger)
She has demonstrated great dedication to achieving her goal (built a ship and used it to find an Exo frame)
She can act outside the interests of the Consensus and the City if necessary, as she is not a Guardian
Most importantly, the Vex would not recognize her (as they would if she were Maya, having accurately simulated Maya's mind 227 times), meaning they may not consider her a threat. This is supported by the fact that we never actually see her fighting Vex directly, which could also explain why she seems to truly enjoy crushing that Vex shell beneath her heal in the cinematic. I believe the unofficial title of “Exo Stranger” was given to Elsie by Lakshmi-2 as a sort of joke referring to the fact that neither the Vex nor Rasputin would recognize her. As long as all she does is move peacefully through time, the Vex may allow her to do so freely, or at least with minimal resistance. This is supported by Preadyth's observation that she seems to come and go from the Vault with relative ease and frequency.
This theory provides plausible explanations for every line of dialogue from our lengthiest interaction with the Stranger:
Elsie was not a Guardian, “not forged in Light”, it gives her a reason to be angry with the Traveler (her sister was a Guardian), “A side must always be chosen...even if it's the wrong side” (Ana died at Twilight Gap), the Vault and Preadyth sets a point of understanding and contention between her and the Vex, “They brought us here...Evil so dark it despises other evil (the Taken)”, when asked for direct assistance, she insists “my path is my own,” indicating that she has a goal that she feels is possibly more important than helping our character in particular – that goal would be finding a timeline without war, which would double as a sanctuary for her lost sister. “But where our paths cross, ground could break.” I believe here, she is implying that at some point in the future, she will need us to use the device. If an Exo is better suited to using the Device than a human, what might be better still than an Exo? A Guardian. Ulan Tan theorized, Ikora Rey confirmed the possibility, and our Guardian personally found physical evidence that all Light may be connected across space and time.
Finally, I believe the person she is speaking to through her comm system while on Venus is a member of the Inner Circle, the leaders of the FWC. Knowing the time machine would be dangerous in the wrong hands, they loaded it onto Elsie’s ship (after a snazzy new paint-job, of course) to keep it hidden and moving. A single ship in all of space is harder to find than a room in a Tower in the Last City on Earth. The Inner Circle guards the machine, which contains her “real” body, while she is away searching the timelines for a Guardian who can help her alter the past to prevent the Darkness from ever existing, or perhaps from coming to our solar system. This would not only prevent many years of war and the Collapse, but would also provide no reason for Ana Bray to have to die at Twilight Gap, satisfying Elsie's original goal. Whatever that may entail remains to be seen. Perhaps purely coincidentally, “Inner Circle” starts with same two letters as another group we know of, the “Ishtar Collective” – but that is a post for another day.
I have attempted to present the most complete picture possible with the information we currently have available. I'm excited to hear what you lore-hounds think about all this even if you disagree with my conclusion. Very sincerely, thank you for your time (get it, time?)