I find it interesting how out of the enemies we fight (Fallen, Cabal, Hive, Vex) Only two, the Hive and Vex, have been confirmed to worship/draw power from the deep/darkness but the speaker still groups all of them together as "minions of the darkness". This, like many things, makes me wonder about the Speaker's motive. I find this especially interesting since we know the Fallen don't want to destroy the Traveler and were even once blessed by its light. As for the Cabal we don't know what they would do with it. The Fallen came for the Traveler yes but it's because before the Traveler came to our system it the visited the Fallen (originally called the Eliksni) but the Traveler ran after Oryx and the darkness came to destroy the Fallen and take the Traveler's light. The Fallen followed the Traveler to our system hoping to reclaim its light and use that light to retake their home world. We don't know that much about the Cabal and their goals on Mars or why they came to our system in the first place. My thoughts are that the Cabal want Earth as well as Mars and that they are after control of the Mars warmind Charlemagne and use him/it* to combat Rasputin who would potentially seeing the power of the Cabal empire use his arsenal of weapons of mass destruction from taking Earth as there own. No matter whether or not my speculation on the intent of the Cabal is anywhere close to what Bungie intends to do with the Cabal their bases on Mars show that they are there to stay and aren't going anywhere without a little encouragement from the guardians. I find it interesting how the speaker doesn't distinguish between the true minions of darkness (Hive, Vex) and the other two (Cabal, Fallen). What do you think, feel free to put any of your opinions and theories down in the comments but please try to stay on topic of what I talked about here. *We aren't sure if Charlemagne is a true AI like Rasputin as they could have been developed by different group meaning that their software/mind could differ fundamentally in its construction.