Maybe the self defense laws suck, and using a gun would send him to jail.
Not in Michigan. Any use of up to deadly force is authorized, with no duty to retreat, if a person doing the shooting/stabbing/running over with car is not committing a crime themselves and is not trespassing. If they feel they they, or anyone else is in danger of death, grave bodily harm, or sexual assault.
Even better, if it is covered under the self defense act, you're immune for criminal prosecution, and if the dirtbags family decided to sue you in civil court, the judge will toss it and make them pay your legal fees (as required by above mentioned self defense act)
Since 2006, these civil lawsuits have become almost non-existent in MI.
Also, being a 'superhero' might be construed in a court as out looking for trouble. If I go out looking to find someone trying to hurt someone just to shoot them, I'm not really covered by the self defense act (I think)