Unchained Overlord: The Final Settlement

Ethan Stone took a charge that belonged to someone else and served three years for it, because the woman he loved would otherwise have gone in his place. He came out on the appointed day and found out within hours what had been arranged while he was inside. Prison gave him two things: a knowledge of medicine and pressure points he learned from another inmate, good enough to bring people back from injuries hospitals had given up on, and the physical hardness to end a fight quickly. He uses the first to treat patients nobody else will touch, which brings him money and people who owe him, and he uses the money and the people to work his way back toward the men who put the case together. The paperwork behind his conviction comes apart as he goes, and the ones who signed it start losing what they bought with it.