As central a figure in Murdock's life as Uncle Ben was to a pre-Spider-Man Peter Parker, Battlin' Jack Murdock would offer some unique insight to how the role of Matt Murdock came to be Daredevil. Arranging Jack Murdock appearances in the show via flashback would offer a great deal of information on just how Matt would choose to take up crime-fighting, and, more specifically, organized crime. A boxer whose failed professional career led him to use his brutal talents as an enforcer for the mob, Jack Murdock isn't exactly a saintly figure who guided his son with great advice about power and responsibility. Jack's story is one of redemption and finding his lost integrity, which could make for a powerful background story that would evolve over time.
Image Credit: Reid Harris Cooper