Here's Poison Arrow...
Here's after SoC....
!@#$%^@
Well, at least now I know that you CAN capture stances from bosses. The problem is that you can't see them being used as far as I know, and I wasted one SoC. Oh well, guess it would have been the same if I just trained the skill... but there's some confirmation for anyone who has been wondering if you can capture stances or not.