Harry Potter: Professor with a D&D Panel

Lynn was transported to another world with a D&D character panel. After discovering the perfect place to grind for experience, he spent ten years training alone until he reached Level 11 and became an archmage capable of casting sixth-circle spells. Having never encountered another human during all that time, he was caught completely off guard when an elderly man with a long white beard suddenly came to visit. Even more unexpectedly, the old man introduced himself as Dumbledore. Raw: Hogwarts: The Ninth-Circle Archmage / Hogwarts: The Nine-ringed Wizard — Description from novelcodex.org