character portrait of a graceful beautiful mermaid, art style by Greg Rutkowski and Mohrbacher and Gerald Brom and H. R. Giger, deep underwater scene, dark and moody, rays of sunlight, faint volumetric god rays, grim crushing atmosphere, trending on artstation, masterpiece, claustrophobic, dizzy, sharp focus, 8k octane beautifully detailed render, post-processing, extremely hyperdetailed, intricate, epic composition, grim yet sparkling atmosphere, cinematic lighting + masterpiece, trending on artstation, very detailed, Art Nouveau