THEORY The Original Crota's End Fireteam May Still be alive
Guys, so we all know that Eris Morn saw her whole fire team die, right? Well this theory debunks that. My theory is that Toland, Osiris, Xur, and The Speaker were all part of Eris's Fireteam. I know what your saying, "What about the 6th member?". Well this character could be released in a future DLC. Or, It could even be one of the Vanguard mentors. Or the Bounty tracker, but how? Remember that pic of the Frame holding the sniper rifle? After failing to kill Crota (or maybe it malfunctioned during the Raid) they got their gun rights revoked (if they did malfunction they could've have killed/fatally injured a Fireteam Member, such as Xur or The Speaker. That could be why we've never seen their faces). Another theory cans be That Dredgen Yor, was the 6th member. If you pay attention while ADSing with Thorn, it has a triangle on it that looks like the [i]String of Curses[/i] perk triangle (this could also prove that Toland and Dredgen Yor were allies. And that they turned on each other fusing their lives together, like [i]Harry Potter and Voldemort[/i] have their wands).
I hope you enjoyed my theory! Feel free to reply with your thoughts!
EDIT: I just read the grimoire. I didn't know about that though! So yeh.
Way off dude. Toland was exiled for experimenting with hive rituals, Osiris fate is unknown but after the queen says to send a crow to mercury after Skolas is interrogated I believe he's been researching a connection between the Hive and Vex, as the queen also says to inform our new friend at the Tower as well. Eris came to her with the Speaker to ask for her help and to "end Oryx" (Queen 2 Grimoire).