Lionheart (1990)

"When the streets are a jungle... There can only be one king."

Lyon Gaultier is a deserter in the Foreign Legion arriving in the USA entirely hard up. He finds his brother between life and death and his sister-in-law without the money needed to heal her husband and to maintain her child. To earn the money needed, Gaultier decides to take part in some very dangerous clandestine fights.