The only thing that ever cut me close were the burrowers at the GMS and that was a whole can of worms to deal with. Then junkyard was hard at points but it was because for some reason my stealth wasn't working properly. I activated it but with the exception of the first or second map I was detected as if I was never in stealth in the first place... Now it could have been that my stealth was too low but actually that was not it because a character with the same stealth values in another run was able to stealth all the times and get proper engagements going so it was some sort of bug that made fights more difficult than it should have been. Still it is a bit tough with quite a few dogs and the mutants. Humans are incredibly easy to deal with once you have locus of control, bilocation and force wall, especially because you stealth into optimal position, throw the bilocation, throw the wall (cause you have enough AP for both) and it's unlikelly any will surive long enough to come to attack you and even if anyone does, you only need to make sure that when the force wall disapears they will still have to waste a bit of movement so they can't attack you. Then you got damage spells to kill them and even if they don't kill them which at this point it's as likelly to happen as a nuclear explosion inside the caves happening, your spells do have utillity stuns to them anyway... At least 2 of them.
Course I never dealth with enemies that could actually use stealth.
