1girl, arknights, bikini, black_bikini, breasts, casual_one-piece_swimsuit, cleavage, criss-cross_halter, demon_horns, hair_between_eyes, halterneck, holding, holding_sword, holding_weapon, horn_ornament, horns, long_hair, looking_at_viewer, medium_breasts, navel, official_alternate_costume, one-piece_swimsuit, open_mouth, purple_eyes, red_hair, solo, stratoz, surtr_(arknights), surtr_(colorful_wonderland)_(arknights), swimsuit, sword, thighs, very_long_hair, wading, water, weapon, white_one-piece_swimsuit