Trying to come up with a reasonable conversion of an ability from an old d20 gunslinging/western supplement called 'Winged Him'. Essentially, X times per day, you can change an attack from 'missed' to 'dealt minimum damage'. The catch, of course, is that you can choose do to this after you've determined the attack result, something that HERO can't really do as far as I know, without incredible amounts of handwaving.
All I can think of off the top of my head is a Naked Advantage of One Hex Accurate on a relatively small amount of RKA, with a limitation that it automatically hits the shoulder or upper arm location. You'd still have to declare it before the attack, but it seems a potentially decent way to ensure you do at least a little damage.
Other options appreciated.