The Reincarnation of the Forbidden Archmage

One day dungeons suddenly appeared Humans with awakened skills then set out to face these dungeons in search of hope and riches Our protagonist Saeki having no skills is considered incompetent in order to earn enough money for the treatment of his little sister with an incurable disease he decided to become an adventurer Saeki has a secret in his previous life he was the most powerful mage Since his reincarnation he has to level up to regain his former powers This is the story of an incompetent who will turn the world upside down with his power