In that scenario he could become a closed timelike curve: go back, become the being that invented magic in the first place, and program it to record the brain states of everyone at every moment in there lives for future recall given a spell or ritual that he would then know. This could also explain the “Atlantis erased from time” business. It would rely on magic changing the laws of physics in a way that allows magic time travel to operate before magic existed—or for the invention of magic to have happened outside the timestream.
In that scenario he could become a closed timelike curve: go back, become the being that invented magic in the first place, and program it to record the brain states of everyone at every moment in there lives for future recall given a spell or ritual that he would then know. This could also explain the “Atlantis erased from time” business. It would rely on magic changing the laws of physics in a way that allows magic time travel to operate before magic existed—or for the invention of magic to have happened outside the timestream.