The Mob Boss is a character that makes a deal with Fighter, wanting him to smuggle time bombs into the vicinity of a few guards. Fighter returns to collect his pay along with his friends, hoping they'd all receive equal payment for the deeds he alone accomplished, but the Mob Boss threatens to break the Light Warriors' legs for their incompetence. After realizing that the remaining guards followed them there, the Mob Boss threatens to kill them all and THEN break their legs. The Mob Boss then escapes to frame the Light Warriors. He later comes back to his old hideout after the Light Warriors hijack it for their protection racket. After beating his right hand man to death, he threatens to smash the Light Warriors' skulls for taking his place as the city's crime lord. After Thief's failed attempt at summoning ninjas, the Light Warriors end up attacking him with burning ninja corpses and fire spells. With only 10 hit points, he collapses, presumably dead.
In the Epilogue, it's revealed he's still alive, with his right hand man, who is holding the 'doin fine' sign, similar to the ones the dark warrior used earlier.