Protagonist with Evil Story Goal in Novel
Question: How do you write a good novel in which the protagonist has an evil story goal? Answer:
Though they are more rare, there are stories told from the point of view of an immoral or villainous person. Shakespeare's Macbeth
is one example. A Clockwork Orange
In first person narration, reading such a story feels like having a mobster mistake you for his best friend. On the one hand, it's flattering to have him share his life story with you, while on the other hand you can mentally step back and pass judgment on his crimes.
Traditionally, villainous protagonists were the subject of tragedies. You read such stories to see how their mistakes and character flaws led to their downfall. Tragedies were lessons on how to not lead your life -- don't be greedy, selfish, overly ambitious, etc.
More problematic are the villainous protagonists who win in the end. Their stories can be disconcerting because they offend our natural sense of moral justice. The thematic message they deliver is a sense that something is wrong with the world (society, the universe, God, etc.). A system that would allow a villain to win must itself be a corrupt and immoral system in need of reform. Such a story is disturbing because people like to draw comfort from the notion that they understand the rules of the world, and that understanding makes the world fair and just. Seeing a villain win destroys that illusion.
So I would suggest you decide what your thematic message will be. Are your writing a tragedy or an indictment of the world?
Next, it helps a lot if you can make your villain appealing. This may mean giving him charm, humour, a backstory that evokes sympathy, flaws that the reader can relate to, or perhaps one or two traits that are admirable.
Consider that Ebenezer Scrooge has his endearing qualities (he enjoyed games and dancing). Even Satan in Paradise Lost
comes across as admirable for his championing of individual freedom: "Better to reign in Hell than serve in Heaven."
Finally, it may help to give your character an inner conflict. Show us either the arc of his downfall or (if he starts out nasty) let him be pressured to reform but ultimately refuse to change.
Best of luck.