It sounds fair, but the problem with that is duels will end too fast.
For PvM, I made a sorc w/ total focus on necromancy, and all the monsters died w/ one wail of the banshee because it's DC 40 or something, but I digress.
I understand what you want accomplished, but as far as I am concerned, there are many other damage spells that work just as well. Besides, those with high Relfex almost always have Evasion, and you can't BAN that as that's within a class ability.
ADD: As for Monks, they have low AB, so their abilities are hard to use. You gotta be really lucky, or hope your opponent is a bad dueler.