Lacking clear motive and goal
Question: My story is about how one man works his way up into society so he can tear it apart from the inside. I feel that's the main "goal" of the story (to show how he does this), but I'm not sure how to make it interesting. The man comes into this society from abroad, but I'm struggling to think of a motive or goal for him, since by the end of it he will have complete power over the area. I can't think of why he should want to do that, but it can't be too extravagant (kill everyone in sight) because that will point away from the theme of the book.
I suggest you do some research into the psychology behind ambition or perhaps historical precedents. You may well ask yourself what motivated Genghis Khan or Alexander the Great.
Some psychologists might say that conquerors seek revenge for early childhood trauma. Certainly revenge has been a common motivation for protagonists. Since your protagonist seems to pursue a covert route to power, you might also do some research on sociopaths and psychopaths.
Bear in mind that your protagonist may not know himself why he does what he does -- which could be the basis of his inner conflict. He may only realize at his personal crisis the cause of his quest for power.