1girl, arknights, barefoot, beach, beach_towel, breasts, completely_nude, crossed_ankles, demon_horns, feet, from_above, full_body, horns, large_breasts, nipples, nude, one_eye_closed, purple_eyes, qianyuu_(senba), red_hair, sandals, shade, sitting, solo, surtr_(arknights), surtr_(colorful_wonderland)_(arknights), thigh_strap, towel, unworn_sandals