I posted this above yours, but I like the idea. The main counter argument I have is - why are we so intent on fighting back our own defense? Wouldn't Rasputin let us know when one of our Ghosts hack into terminal after terminal, or let the Speaker know? Or does Rasputin believe that his Vex defense still has a better chance against IT than we, the guardians, do. If the latter is true, then since the Vex are biomechanical, then maybe they (like him) adapt and learn from their enemies. Rasputin would then be essentially using Guardians to "train" his defense to be even stronger for when IT returns for the final battle. #conspiracy As a sidenote - Dinklebot does speak of the Vex destroying planets within days. He talks about that at the same time we learn that the Vex are vacating Mars (I think). So maybe the destroying of said planets are the final stages of their departure? The Vex inhabit a planet, once invaded to where they can no longer defend, they depart and destory the planet so nothing is left behind for their enemy?