In halo 4 description, it says "ancient evil that threatens the the entire universe". Ppl thot it had to be the precursor but in halo cea terminal 8 guilty spark says "and if the full array sas attuned by 00 then the overlapping waves would magnify exponentionally cascading to cover all known star systems. and that only considers the firing of a mere 7 halo rings, not the original 12. sterilization would spread farther than most forerunners feared we could reach." this means, i think, that the didact and his friends have spent 100k hears in requiem and made themselves into the robots, and are now planning on fleeing requiem and firing all 6 halos and in the future rebuilding all so sterilization will cover the entire universe, to permanently end the threat of the flood and precursor. this is why cortana say " i will not allow you to leave this planet". I think there are 2 arks so they can find it and build another 6 halos. Or maube they have halos in requiem? Further proof : "he never got a chance to fully execute his proposal. The council saw to that. but if something were to happen with one of the halos, if our tools were ever used against us... Long plans indeed." I think this is truth and i sould love to hear reasons why not? [Edited on 06.30.2012 2:28 AM PDT]