Exo Stranger

The Exo Stranger is an Exo that roams the wild. Her purpose and intentions are unknown, but she appears to be interested in the player's activities and keeps tabs on them when they venture outside of the City. She is first seen watching as the player escapes from the Cosmodrome. . During the sixth Story Mission, she is spotted by the player, looking down at them from the rocks that line the edge of the gorge where they are attempting to gain entrance to the Temple of Crota. When the player is about to enter the Chamber of Night to save the Traveler from a Hive ritual, she is able to send a transmission to them telling them they need to see her on Venus. There, she delivers a mysterious warning to the player. She is the one who warns them about the imminent Vex Threat, and that the only way to heal the Traveler is to destroy the heart in the Black Garden.

The Stranger appears to be working for an unknown faction who know more about the war against the Darkness than the Guardians do. She possesses much technology that even the Ghosts don't fully understand; she is capable of appearing and disappearing out of reality, and her rifle has parts that "shouldn't yet exist."

Gameplay
The stranger appears in the following missions:

In the missions A Stranger's Call, she was talking to someone. The identity of that person or persons has yet to be revealed. Additionally, according to the flavor text of the last quest step in the "Not Forged From the Light" quest, Praedyth or his Ghost may have seen her at some point. This is implied to have been a recurring occurrence.
 * "A Guardian Rises"
 * "The Dark Beyond"
 * "A Stranger's Call"
 * "The Black Garden" (Final Cutscene)

Quotes

 * "Well fought… Many Guardians fell… …Strong ones… …But you made it here… …Don't let them find you…"
 * "I wasn't talking to you, little Light" (speaking to the player's Ghost)
 * "It doesn't matter who you were, only what you will become."
 * "Ah yes. The Awoken. Out there, wavering between the Light and the Dark. A side should always be taken, little Light... Even if it's the wrong side."

Trivia
The Exo Stranger is voiced by Lauren Cohan.

List of appearances

 * Destiny