Shishimai

A dark-colored cyborg made of unusual metal who frequently switches out his limbs as needed. Notably, he has never called himself by any name; he's called Shishimai by Jiga Kirishima and Fay due to his resemblance to the traditional shishimai lion dancing costume, and he's called Obsidian by Khamsin, most likely a codename due to his black color. He is distrusting of other people and is often treacherous and sadistic.