1girl, arknights, breasts, crossed_legs, demon_girl, demon_horns, hair_rings, horns, large_breasts, long_hair, looking_at_viewer, official_alternate_costume, open_mouth, purple_eyes, red_hair, saiko_(saisaka), sitting, solo, surtr_(arknights), surtr_(colorful_wonderland)_(arknights), swimsuit_cover-up