1girl, arknights, ass, bangs, black shirt, black thighhighs, bottomless, demon horns, floating hair, from behind, hair between eyes, hand on hip, heart, horns, iumu, long hair, looking at viewer, looking back, purple eyes, red hair, shirt, short sleeves, sidelocks, simple background, solo, surtr (arknights), surtr (liberte echec) (arknights), thighhighs, very long hair, white background