laevatein (la3vatein), laevatain (arknights), surtr (arknights), arknights, arknights: endfield, commentary request, highres, revision, 1girl, back, bare shoulders, black dress, black horns, closed mouth, demon girl, demon horns, dress, from behind, hair between eyes, horns, index finger raised, long hair, looking at viewer, looking back, purple eyes, red hair, shoulder blades, simple background, solo, very long hair