Narrator. Captivating tone, voice, and gentle strength. Booming tone to Mysterious person either or both works here. Giving this a final boss that has class tone like Ansem Seeker of Darkness or Xemmnas from KH or any other main villian would be fantastic. Whether he will be a villian hero or otherwise will be up to the viewer;)(even regular  attractive is excellent for this role. Somethig That narrator would do.