Does STSF go off of a forms INT or the shapeshifter's INT?

I'm asking because I recently fought a warrior with STSF and about 10 rounds into our first encounter, I couldn't flee. This is *after* taking the unpredictable edge.

Are those charges supposed to build that fast? Hard to imagine fighting a STSF without the edge (assuming there's a difference). And I imagine the net result for most would be to avoid that person for the rest of your login.

Lastly, to anyone playing STSF warriors, it seems pretty childish to taunt someone for not fighting you a second or third time. No one owes you another battle especially when they cannot flee/dodge/parry/hit you. If you want more action, don't pick STSF next time.