The Old King and the Faceless Adventurer

Lemuria, the city of adventurers. There’s an adventurer who challenges the world’s oldest dungeon there, the “Odoriji Spire”. Other than being a foreigner (otherworlder), he’s an ordinary and unremarkable person who doesn’t have a single party member and hasn’t produced any results in 10 years of adventuring. When the only sword he has left is broken and he is ready for it all to end, a snake appears in front of him. Calling himself an old king, the snake bestows power unto the adventurer with nothing… but the price he must pay is not a small one.