jhorleb wrote:
So the aura of negation has a chance of hitting all in the room with a dispel effect? Including allies?
No, it only normally only affects one target per use of the aura (although if you get a great skill check, the aura will not drop after that triggering). The verbiage about not controlling it's affect refers to the fact that the skill does not have a target. Whoever attacks the barbarian first will be the one affected by the aura (in practice this would usually be the guy who would get counterstriked). The barbarian does have more control if they initiate the fight instead of being attacked.
jhorleb wrote:
Also does the barb's worn MR get included in the strength of his negation aura?
Yes, it does. This ability uses the MR rules, not the dispel rules. Any MR you have applies, but its not the full percentage of your MR. So you don't need to train MR to make use of this skill, but it won't work very well without training.