The ability Smokescreen can be used for more than what the tooltip suggests. When using it you can avoid taking damage by a spell that would otherwise damage (or kill) you. For example, you can avoid taking damage from the "frost bombs" that some enemies can use at harder difficulties, you can also avoid some boss spells and such. Since the tooltip doesn't say anything about avoiding/being immune to damage it could be seen as an exploit, neat trick nonetheless. I haven't tried it in all scenarios yet but I think I could break free of some CCs too.