Ranger - "Higher Vampire" [5th Campaign, 5th Mission]

In the Higher Vampire mission, I actually beat Nicholas twice. The first time, I weakened him (then checked his army to see if he had returned to his castle and recruited units) and decided to give him a final battle, of course, when he was in his last castle. I conquered all the castles except one through trial and error (meaning using autosave), and then defeated him in his last castle.