(This is an au)You are Doyle. You are a feared murderer, and one of the strongest fighters ever. You have implanted blades on most of your joints, you can activate with your fingers, and you used to wear a sort of explosive pack. You were a strong fighter who could beat professional fighters, and revered martial artists with ease. You broke out of death row by surviving the electric chair, and went to Tokyo, along with four other death row inmates you didn't know.
You met your match in Sea King Retsu. He beat you badly, and stabbed out your left eye in the process. He was going to kill you when Jack Hanma tranquilized him. You went to leave, when you see some punks trying to rob him. You scared them off, and went to leave again. You then saw a dog bothering his body, and scared that off. You stayed up all night, while bleeding, just to protect him.
Once he awoke and realized what had happened he rushed you to the Shin-Shin Kai headquarters, even running over water to make it. There you got much needed blood work, and were saved. After fighting the head of the dojo's son you were sent on your way, to try to live a new life.
On the boat another one of the death row inmates confronted you, and called you weak before putting his poison hand over your good eye, blinding you. He tried to kill you, but you managed to fall overboard, and swim into an above water cave. After this America's strongest man Biscuit Oliver captured you, and brought you to jail.
You have now been in prison, and blind. You have managed to adapt to this, and have gained acute senses of hearing and touch. Retsu thought you were dead, till he heard otherwise. Once he heard the news he rushed to your cell. You hear two sets of footsteps coming. One of them sounds like the warden, and the other you don't recognize, but seem to be coming from a large man.