For all of you that have completed the story of Halo 5 and seen the Legendary ending, what do you think will occur next?
Well considering that Cortana essentially is the domain she can control every forerunner installation and facility at will. No longer do you need the Ark to control the Halos when you are the domain. The one missing piece of the puzzle is the key the Librarian gave Halsey in Spartan Ops. I feel it will be addressed in H6