How about 'Mindscramblers'. A pair of mechanical gauntlets that send electrical shocks to the enemies brain with every blow. They would have like random effects though, meaning that you can just as easily infuriate or motivate the enemy as well as you could confound him or convert him to your cause. I've always wanted something like that... and i always like weapons where anything can happen. It kind of breaks the 'gun' mold.


You could also use a patronus charm if mindscramblers aren't your thing...