Long ago there was an ancient civilization that was very advanced.  However
jealousy and greed were never rid of.  Two factions of this civilization caused
a great war where much of the world had been laid to waste.  These great ones
banded the portals and the tower together to create a new world (a matrix)
where they could escape to until the world had healed.  These great ones with
the most knowledge became the gods and the others devolved into the mortals of
the realm.  Some of the mortals realized that this realm was fake because they
were uncomfortable with the lack of technology and thus woke themselves up and
had great abilities in between those of gods and mortals due to this.  They
were running rampant and threatened to destroy the world so the gods created
the sentinels who were part of the system but at the same time partially freed
although their loyalty remains with the great ones.  All that remains of the
great ones in the realm is a slowly diminishing supply of high-tech items.