Former Demon King's General

The Former Demon King's General is a currently unnamed retired general of the Demon King's army who now protects the Demon King's Castle. Serena claims he is the strongest mage in the world, and more dangerous than the Demon King.

Appearance
He wears a pure white robe and mask, and has a similarly colored staff. Underneath, he has a pair of pure white wings.

Personality
The Former Demon King's General seems to believe in "proper" battles and dislikes sneak attacks. He talks in a formal and dramatic fashion. He can be pragmatic as well, attempting to exhaust Megumin in a battle of attrition.

History
He was formerly the most senior Demon King's general. After Wiz single-handedly stormed the Demon King's Castle, he stepped down to focus on defense.

Abilities
He is presumably extremely powerful; Serena claims he would be able to simply blast away all enemies with powerful long range magic. Though he is confined to the vicinity around the Castle, while he remains there he can draw unlimited mana from the demonic realm.

Magical Barrier: He has as powerful protective barrier around him. Serena claims that the whole Crimson Magic Clan would need to unleash their magic on him to have any effect. He was able to take a hit of Megumin's explosion spell, though it did manage to injure him.

Regeneration: He has powerful regenerative abilities; he was able to fully recover from Megumin's explosion in a matter of second. This ability does seem to have limits, as it could not keep up with multiple consecutive explosions.