Invisibility, fog, grease and featherfall are GROSSLY useful.
Friends is even more useful than that.
Fog would be much more usefull if it would work as tooltip say ...
Sadly enemies are totally able to hit you in middle of fog by their ranged attacks.
Friends is doublle edged sword ...
It requires taking some risks, or metagaming to use it most effectively ... but over and over, it can easily get you into lot more throubles.
