A dark brown-skinned Superman, dressed in a sleek, capless black suit, undergoing healing through advanced nanotechnology. His clean-shaven head and full beard add to his powerful, commanding presence as he faces the viewer. Ultra-realistic visual effects show intricate nanobots in action, repairing his wounds and restoring his strength, with metallic particles swirling around his body. His expression is intense, and the scene is rich with detail, emphasizing his resilience and the cutting-edge technology at work.