The Underground is an area that exists in Custom Robo Arena. A ton of Illegal activity exists within this area. The hero will be able to access this area once he obtains the Dark Commander Mark from the Doppelganger.
Battles
Below are the battles able to be fought in the Underground:
Cleaver data:
Robo: Violent Boar
Gun: Sling gun
Bomb: Scythe bomb
Pod: Cleaver pod
Legs: Cleaver legs
Kindgal data:
Robo: Freya
Gun: Cleaver gun
Bomb: Sling bomb
Pod: Scythe pod
Legs: Kindgal legs
Underground Shop
Below are the items purchasable at the Underground Shop: