Unleashed

Unleashed is a movie starring Jet Li, Bob Hoskins, and Morgan Freeman. A man enslaved by the mob since childhood and raised into behaving like a human attack dog escapes his captors and attempts to start a new life.
Raised as a slave, Danny is used to fighting for his survival. In fact, his "master," Bart, thinks of him as a pet and goes as far as leashing him with a collar so they can make money in fight clubs, where Danny is the main contender. When Bart's crew is in a car accident, Danny escapes and meets a blind, kindhearted piano tuner who takes him in and uses music to free the fighter's long-buried heart.