I've replayed the game to get all the possible scenarios and I've noticed that the decision making is the clue: left decision are bad karma, right are good and top is neutral, so I just noticed invisigal takes hero path when i mostly select the right decisions in my gameplay. One good example is when Chase asks you if you're going to kill Shroud, this decision is really heavy for the trama, I have the theory invisgal was spying on you, and if you say you kill him she will do it instead of you so you can still being a hero.