Diablos Stage is the Inferno. The Inferno is a fiery island and is in the shape of a fireball. The Inferno is a fiery area with active volcanoes and a deep red volcanic rock that makes up the terrain. The volcano is seeping magma through cracks in the floor and giant magma geysers shoot out fire. In the right side of the screen a bunch of Aztec ruins remain such as the head of the Quetzalcoatl and an Aztec pyramid.
How the Inferno looks in game.
All information here was stuff I had come up with. All Primal Rage 2 information especially images have been brought up by me. Gruntzilla94 2016