オーバーロード 1 不死者の王 by Kugane Maruyama

不死者の王

A veteran player of a dying MMORPG finds himself trapped in the game's world as his avatar, a powerful skeletal overlord, after the servers shut down. With the game's NPCs inexplicably sentient and fiercely loyal, he inherits command of his guild's tomb fortress and its monstrous guardians; forced to confront this new reality, he adopts his guild's name as his own, tests the extent of his power and the loyalty of his followers, and begins probing the unfamiliar world to learn whether others like him exist and to secure and expand his domain.