Handmaiden’s Power from Pain talent is supposed to add 5% crit chance per enemy hit with the dash, stacking up to 5 times for 25% power.
What happens is that you don’t get any crit chance at all, even if you get the stacks.
I have tested and confirmed this by going on the mod realm and hooking into the random function, then checking the numbers when it rolls for crits. The crit chance stays the same, stacks or no.