when the soldiers were children, experiments were put on them to make them super soldiers, Yakov was fed powders and poison so that he was invulnerable, from which he became paranoid and absolutely trusts no one, and he considers you a spy. All 9 soldiers who were once experimented on live in the barracks and are not allowed to leave the camp. After the second experience, they were made immortal, their hearts are mechanized, and their blood is black. Yakov is a soldier of a special detachment.