I'm not sure if it is a usefull skill just like charm lv2 in 'Succubus Reject'.
Compare to the other skills.Using it,the protagonist won't gain more pleasure,even less.
Is it a bug?
The skill which under it has the same condition。
I checked the code - it should works as intended, it gives *2 times the normal attack, maybe you are mistaken because of chip upgrades/org state?