This concept design is heavy inspired by Disgaea D2 inner core of the Netherworld where Laharl faces against Xenolith. In this one, it bears a resemble look of the inner cave but I added some more detail onto the tree at the very end of the cave where is slowly flowing energy sources from the netherworld's planet core. This is the place where the god of Hades stores his powers and malice from Humans or any intruders who enter. Its also a battlefield for overlords from different worlds (or Dimensions) fight to the death without stopping. once the person is defeat or killed, then they must leave the place immediately or they will either be engulfed in rage to kill or Die by the intense godlike malice resonating inside the cave. Side Note: If one stops the battle, they will automatically be consumed with great infinite amounts of Blood lust to kill. So basically if any demon wishes to enter here, they must know the rules and guidelines of what is to come when entering into this cave or they will suffer dearly. Eteernal Evilest is the inner cores name but the outside name is called Mt.Emembolo Mt.Emembolo (my language means Mountain Revenge.)