Overlord, Vol. 3 (Light Novel): The Bloody Valkyrie, Hardcover/Kugane Maruyama

Lord Ainz has made great progress moonlighting as the indomitable hero Momon, but what should be a moment of triumph is shattered--by news of rebellion. He vows to find out what has happened and to defend the honor of his guild and home--Ainz Ooal Gown.