1girl, arknights, barefoot, beach, beach_towel, bikini, black_bikini, breasts, crossed_ankles, demon_horns, feet, from_above, full_body, horns, large_breasts, one_eye_closed, purple_eyes, red_hair, sandals, senba_(592683801), shade, sitting, solo, surtr_(arknights), surtr_(colorful_wonderland)_(arknights), swimsuit, swimsuit_cover-up, towel, unworn_sandals