The Underground Empire is a villainous group lead by the enigmatic Dr. Hell. It strives for world domination through the use of the Mechanical Beast Girls and any other means it can acquire. However their plans are rather convoluted and unsuccessful. Unlike its counterparts that were based on the island Bardos, the Underground Empire is stationed at a cave in the Chichibu Mountains in Kanto.
History[]
When the empire was founded is unknown but Dr. Hell seems to have been working on his plans for world domination for years. Recently the empire started to attack Photon Power Town to acquire the Photonic Energy of the Photon Power Laboratory. However this and various other exploits have been stopped because of the efforts by Robot Girls Team Z. Eventually after many failures, it was acquired by the Mycenae Empire.