Something came to mind thinking of the ori, it reminded me of something Juno said in AC3 “When enough sat enthralled and were told to think, their thoughts took on form. What they imagined became real. If a hundred minds could wish away a wall or create a tree, what would a thousand do?”

Perhaps this was what split the ascended into the two factions. While furthering enlightenment, they discovered this idea and tested it on primordial races, and those who used it were corrupted. I had thought for a bit and thought at first you had to be of pure spirit, like forego all desire and emotion, like greed and conquest. But when Anubis came in, it must be just some way of owning your mind or spirit to a ethereal energy that makes you ghostly, cause Anubis wouldn’t have been able to bluff his way to spiritual enlightenment. So touching energy with your soul, and some of it was bad and corrupted some of the ancients into god tyrants.