ive never found it does anything,
but then again i only invested one point on it..but since it did pretty much nothing at one point..you can see my hesitance for wanting to put more on it. who knows..maybe it works great with more filled, or it just dont work for me, as it seems it doesnt block any other shot except plain cannonballs..and whatever shoots plain cannonballs isnt exactly a threat anyways.
just my opinion, and not meant to be fact of any sort
and maybe im using it wrong.