Heyla and well met!
I had taken the first two Ninja Spy core enhancements with the hope of being able to use my Dexterity, rather than my Strength, for my to-hit and damage bonuses, thinking that Vorpal Strikes would qualify me as wielding a slashing weapon. However, whether it is on or off, I still get the same total to-hit bonus (tested with a Strength of 19, and a Dexterity of 29, then with the same Strength, and Ultimate Wind Stance Activated, bringing my total Dexterity to 33), which means Vorpal Strikes is not being considered by the Ninja Spy core enhancements, correct? Is this WAI, or should I bug report it?
Kookiekobold said this is a known issue and was bug-reported, sometime back.