yui (niikyouzou), ch'en (arknights), arknights, third-party source, 1girl, black hair, black necktie, black pantyhose, black shoes, black shorts, black thighhighs, blue hat, collared shirt, cropped jacket, full body, grey background, grey jacket, hat, id card, jacket, knee pads, multiple views, necktie, pantyhose, prototype design, shadow, shirt, shoes, shorts, single knee pad, standing, sword, thighhighs, weapon