Seems you have to get a perfect score of 4 from 4 checks to pass, one of those being 100 power and the other 28 skill. Even tho the guide said 3 /shrugs. I reloaded a save Iand was able to get 29 skill thanks to the monster girl (105 power and 29 skill). The mod thats mentioned by others works too, I installed it and been playing with it on incase I need it. As you see this game is very easy to miss stuff or bad end you. Annoying as it is. Its not a friendly game to play on your own initiative. A bad choice could ruin the experience. (not counting the obvious ones, as you should always train). I dont like this part of the game.
On aonther note , anyone find it funny how doofus the MC can be at times ? Like being in the ladies toilet hanging with Amber and Liz, but not changing to his female form.. opps!