The only thing i can think of to make the spirit bomb work against a good person is that the essence of the bomb is made of the intents of the collective used, so if a good person collects good peoples energy, it wipes the floor with baddies, if a bad person uses it, and collects energy from bad people, itl wipe the floor with good people. This all assumes that the technique isn't locked to the good spectrum and can be used by any alignment.