This lorebook is really looking like it is potentially setting up Dark Future Eris, getting very heavy Revenge of the Sith Anakin vibes. She is so certain that utilising Darkness is the only way to ensure salvation, could really be her downfall. Really sad for our girl Eris if this is the case and I hope she does not end up as baddie. However, this could be an epic story development in setting up factions for Lightfall - like she says - "The next Collapse is here, and we must abandon our previous misconceptions of right and wrong". I really think this is where the story is going, where everything is so morally grey. As different characters are allying with individuals and races that were once enemies, this can allow Bungie to really emphasise that "A side should always be taken, little light. Even if it's the wrong side"