[Dustin]

Agree that the spell is overpowered; I had to nerf it to a straight HT roll for my games, and rule that those deafened from a previous Concussion got a bonus vs the next one to prevent it being used to spam-Stun large groups of foes.

Hitting an entire hex (as opposed to an individual target) at 10+ yards to place the blast is just not that difficult, so the only fights where it didn't come out were those that took place in a shoebox at immediate melee range.