Dragon Sword: Demon's Fire Book 1 - Dream Walker Chronicles, #4

Erik Eleodum has vanquished a dragon and is called a hero, but his journey into darkness is far from over. After two years away, Erik returns home and wants nothing more than to live a simple life of a farmer. But he knows that isn't possible. The task that the infamous Lord of the East looms heavy, and failure means death.not just his, but the ones he loves. Erik must leave his home once again to fulfill his promise to a ruler he knows he can't trust and, soon, on the road to the cursed tower of Fealmynster, enemies old and new threaten him.
And a new shadow infiltrates not only the real world, but the dream world as well. In both worlds where he exists, Erik must search for answers, salvation, and his purpose, hoping they can be found in the Dragon Sword.