The Ringworld Hero

Waking up with a hangover isn't unusual for a young man. But waking up on a ringworld with a mysterious object in your chest and covered in blood is a whole new level of drunk.
Danny, a 19-year-old engineering student found himself in this very situation, the destined hero of a ringworld and with an ancient artifact forever bound within his body. Now he must learn to master it's use and get along with the elven princess who doesn't exactly like him.