User blog comment:ChishioKunrin/Maidens - Origin of Dust and the Kingdoms?/@comment-25110963-20151216101644/@comment-25110963-20151216102559

Using Final Fantasy logic, this man might have been some advanced being, maybe from the moon(Man in the Moon story), maybe elsewhere, that came to Remnant. He was observing this world. Maybe the four sisters stumbled upon the man.