 A concept unveiled in the manga and anime.As the story unfolds it is learned that there exists a parallel universe adjacent to our own, where humanity reached incredible peaks of technology at the cost of their very nature, to the point where the human species as a whole became extinct after merging its own collective consciousness with the machines they created.Similar to a hive mind, this virtual collective unity threw away individuality and any sort of vestige of human feelings for the sake of power, becoming one cold, ruthless mechanical being bent on a continuous, endless expansion of itself.