Xavier

Xavier is the most experienced mage in the Spiral Spire. He used to be an orphan in the slum, but he later entered the Spiral Spire to study magic. One day, he accidentally unsealed a black ghost from an ancient book, which claimed to be the demon king. Since then, the demon king and Xavier started to inhabit the same body. This uncomfortable situation has lasted for 7 or 8 years. They hated each other, but had no choice but to get along.