You know how oryx has 2 sisters well here is my theory us guardians never found out how Eris really got out of the hellmouth all her fireteam members died but she didn't doesn't that seems strange you anger a god but doesn't kill you very strange if you ask me here is what I think on how she survived down there and came back and why she said my queen Btw Eris is a human not awoken Ok here goes as her fireteam members die she must've came by a shrine which must've been one of oryx sisters and made a pact with one of them she sacrificed her light in exchange for vengeance for her whole fireteams death but she knows she can't do it alone so she turns into a hive member and hide in shadows but her vision starts to lose its light and fade to the darkness she starts to praise the sister and then the doors open to the outside she can finally start on her quest for vengenace she asks the guardians for help which they do killing crota and oryx when and as she goes to the sword and says my queen she must be referring to the sister as in IT IS DONE IVE FINALLY GOTTEN VENGEANCE FOR MY TEAM that's why In the missions she always talks about her fireteam and how they died but certain enemies or things so my theory is Eris will most likely backstab us not because she is evil but because the sister will control her Yep that's my theory :) Eris ain't Evil