BloodCurdle

Not really, the description says "as well as increasing the duration of any existing curses". So afaik, that should mean that the initial stack should last 10 seconds, baseline.

The way Forbidden Curse works is either not clearly explained in the skill description or is working incorrectly. Using a character with -36% hostile effect duration and +0% ability duration, on my first cast of Forbidden Fist the duration for Forbidden Curse is ~ 16 seconds. Considering the tooltip says the base duration is 10 seconds, this doesn't really make sense. Is the duration increase on successive stacks applying to the first stack?