Dark Fantasy Sketch Refinement

Using the provided reference sketch as the exact pose and composition guide, turn the rough doodle into a highly finished dark fantasy action illustration. Preserve the low, lunging forward stance, the clenched arms in front of the torso, the large rounded right shoulder mass, the skull-like head placement, and the sweeping upward motion lines from the sketch. Transform the figure into {argument name="character type" default="an undead armored knight"}: exactly 1 central warrior with a cracked skull face, glowing purple eyes, a snarling open jaw, battered black-steel plate armor, heavy rounded shoulder armor, gauntlets, greaves, and tattered dark cloth. Replace the sketch motion lines with violent supernatural energy: black smoke and purple flame ribbons erupting upward behind the figure, wrapping around the body and sweeping diagonally through the frame. Add a new environment not present in the sketch: a desolate battlefield or wasteland with cracked ground, dust, debris, and jagged dark rock spires in the background. Use a dramatic low-angle perspective, intense motion blur, gritty brush texture, high-detail fantasy concept art rendering, cinematic lighting, and a limited palette of gunmetal gray, black, dusty brown, and {argument name="magic color" default="electric violet"}. Make the final image vertical, dynamic, ominous, and polished, while still clearly following the original sketch’s silhouette and action flow.