So the thing that got me thinking about this is I was wondering how the Purge worked. I just figured that it was a device similar to a Halo array. But then I thought of how do they adapt the technology to work only on the planet and nowhere else, as well as the ones inside the Purge. But then I realized that if a shield world protects the inhabitants from a Halo firing, wouldn't a Halo firing inside have somewhat opposite effect, only killing the ones on the planet? Also, the temple at Crash Site Alpha has an effect similar to the Forerunner gravity well on Requiem in Halo 4, increasing the similarities between Requiem and Chorus. Is there anything I'm missing? Did someone ever address this already and I just never noticed? To anyone reading this, feel free to add on to anything that helps or harms this theory.