1girl, arknights, bare_shoulders, bikini, black_choker, breasts, choker, cleavage, cup, detached_sleeves, hair_between_eyes, hair_intakes, holding, holding_cup, horns, long_hair, long_sleeves, looking_at_viewer, official_alternate_costume, open_mouth, purple_eyes, red_hair, rikuguma, solo, stomach, surtr_(arknights), surtr_(colorful_wonderland)_(arknights), swimsuit, thigh_strap, thighs, very_long_hair, white_background