It should go from 0% to 8% base. Which is really crazy. Finally there's a real way to scale Facebreaker damage, since the global multiplier was useless considering the default base unarmed critical chance is 0%. With this ascendancy node, combined with critical strike support, you can reach like 30-40% critical strike chance, which is absolutely fantastic. And im not even considering power charges, which you could gain from using assassin mark.
Though this game doesn't incentivize much the unarmed playstile, there aren't really good skills for unarmed right now, clearspeed is quite bad.
EDIT: The node says "base critical strike chance WITH WEAPONS", so unarmed playstile isn't included. That's really really sad.