Delsgade

Demon Castle Delsgade (魔王城デルゾゲード) was Anos' castle two thousand years ago. It is now used as the Demon King Academy.

Description
Delsgade is a giant three-dimensional magic circle, so even after two thousand years, it remained unchanged. There is a special magic at its core that allows it to automatically regenerate, even when its most important components are destroyed.

History
Two thousand years ago, Anos killed the Goddess of Destruction Abernyu and turned her body into Delsgade. Towards the end of the Great War, Anos invited Hero Kanon, the Great Spirit Reno, and the Goddess of Creation Militia to his castle with the goal of ending the war. They combined their powers and the power of Delsgade to cast Beno Ievun, a grand magical wall that split the four races into their respective realms.

Treasure Vault
The treasury of the Demon King.

Underground City
A city that Anos designed for the Zeshia clones, based on the Midhaze of 2,000 years ago. Due to being located on the bottommost floor of the castle, a large magic crystal collects sunlight from above and illuminates the city like a pseudo-sun. The shops are manned by Owl familiars, and all transactions are done by filling a stone tablet with magic. The streets are arranged in a circular formation and filled with runes, creating a vast magic circle to ward off attacks.

Trivia

 * Anos can only use Venuzdonoa while in the vicinity of the castle. Despite being repurposed into a school, Anos can summon his castle using origin magic.