Create a concept art piece of a demonic, single-head details concept art robot with numerous limbs, primarily black and orange, set against a 1999 Volcanic Abyss background reminiscent of the Unicron Trilogy. The piece should be in the style of Greg Rutkowski, with inspiration from H.R. Giger and Maxim Verehin. Incorporate a portcullis element and reflect a snarling, academy headmaster character. The output should be a cell-shaded, digital art piece, inspired by the aesthetics of Metal Gear Solid and Dark Souls, but with the dynamic movement of a Tempest by Riot Games. Refer to tfwiki.net for the Unicron Trilogy and incorporate a sense of intense brawl.