A stunning mecha girl with flowing black hair stands with a fierce expression, poised in a dynamic battle stance. Her sleek armor glistens with ultra high-detail as embers scatter around her in the air. The scene is illuminated with cinematic lighting, showcasing a combination of HDR effects and a slight bokeh for a dreamy touch. The environment is rendered in Unreal Engine 5, utilizing RTX technology for a photorealistic finish, with a notable depth of field that draws focus to her intense demeanor. In an intriguing twist, her arms are conspicuously absent, creating a unique visual narrative. Despite the absence, her determination and readiness for battle are palpable, embedded in this concept art piece. The overall composition has an air of mystery, enhanced by realistic light blooms and a subtle watermark signature at the corner.