A villain in a corrupted city sees something terrible happen to a kid. It changes him and he starts to look out for her, helping her in his own way to get justice and to be her guardian angel lurking in the deep shadows.
This is almost like my granddads. When mum and dad met and introduced their parents, my granddads realised they shared a hospital room as a 10 and 8-year-old. That was during WWII and the closest hospital was a military field hospital that was inspected by Hitler himself. When Hitler came round, the soldier thought it would be a good idea to have the two kids (who at the time had no idea who Hitler was) give Hitler a bunch of flowers.