The concept art of an interior of a cathedral in hell could depict a grand space filled with demons, showcasing their malevolent presence. The decorations could be ornate and baroque with an evil golden aesthetic, symbolizing the corruption and decadence of hell. The black background could add a sense of darkness and mystery to the scene, making it more ominous and foreboding. The artwork could be created with a focus on intricate details and ornate designs, highlighting the ornateness of the cathedral and the evil presence of the demons. The lighting could be dim and moody, with shadows playing an important role in conveying a sense of foreboding and danger. | Anything