SpoilerOriginally the human core of the island Wadatsumijima, the Prometheus Core was appropriated by the Neo-UN in an attack on the island, and used for their own purposes as a Festum-controlling tool.
Believing "hatred without reason" to be the greatest power one can have, the Prometheus Core has long since lost any other human emotions, acting as the representation of all the hatred the murdered Wadatsumi citizens feel toward the Neo-UN, and seemingly humanity as a whole.
In line with the core's young appearance, moments of a child-like personality slip through, with him seeming particularly quick to anger when events do not go as planned, or something he views as "his" is taken away.
(Source: Alvis)