Count Blow does add damage to each Pollution Mind tick, though. But even if you could max every single skill and are well equipped I suspect it still would not be enough to be a huge damage dealer in PvP, compared to others (others being the "proper" damage classes and especially the two broken non-damage classes), provided they would be equally well equipped. The mirror and reflection skills can be exceptions, if you are lucky. The problem is that your attacks are slow, damage skills have long casting time and they don't have high enough damage boost (or simply scale with Int) to be proper nukes. In the end you will be the one who is messing around with the opponents putting debuffs on them.