suiryuu (18559651), shining (arknights), arknights, absurdres, highres, 1girl, bare shoulders, barefoot, black one-piece swimsuit, blush, boots, breasts, brown eyes, clenched teeth, demon horns, feet, foot focus, foreshortening, grey hair, hair between eyes, horns, indoors, large breasts, long hair, looking down, official alternate costume, one-piece swimsuit, pointy ears, ponytail, restrained, sandals, shoes, sitting, soles, solo, spread legs, stationary restraints, swimsuit, teeth, toes, trembling, unworn boots, unworn sandals, unworn shoes, white hair