Overlord Movie 3: Sei Oukoku-hen

The Sacred Kingdom has known years of peace behind a massive wall built to keep monstrous tribes outside, until Jaldabaoth appears at the head of a united demi-human army and shatters its defenses. Cities fall, civilians are taken, and the Holy Knights realize that reclaiming their homeland is beyond their strength alone. Their most hated option becomes their only realistic one: seek aid from Ainz Ooal Gown, undead king of the Sorcerer Kingdom and a being their faith teaches them to abhor. Neia Baraja joins the mission to secure his help and soon finds that the ruler she expected does not always match the one she sees. In a desperate war, salvation may come from the person everyone feared almost as much as the enemy.