A player is reincarnated as a skeleton summon in a realistic open-world game, 'The Great Wasteland.' The summon discovers they can evolve and gain power through a unique system involving killing monsters and other players. This summon, previously a player, recognizes the danger their newbie master is in, and decides to protect her, while simultaneously aiming to exploit their unique position to become the strongest solo player in the game. They initiate the first evolution into a skeleton swordsman with an attack speed skill.