Lightening strike is the one that is OP with someone that knows how to use it. A few days ago I ran into 3 guys, I only had banded on at the time. I was mount fighting then one guy jumps off and finishes my mount, as soon as my feet hit the ground I was completely chained blinded until I was dead in about 10 seconds. I don't know if all 3 were using that spell. If I would have seen the 3rd guy I wouldn't have stayed and fought, but I figured with my HP pool I would just try it out with 2. The way mages were in DF1, I wouldn't doubt them having an advantage with higher skill levels and such.