Swordheart

By T. Kingfisher
 
Halla has unexpectedly inherited the estate of a wealthy uncle. Unfortunately, she is also saddled with money-hungry relatives full of devious plans for how to wrest the inheritance away from her.
 
While locked in her bedroom, Halla inspects the ancient sword that's been collecting dust on the wall since before she moved in. Out of desperation, she unsheathes it—and suddenly a man appears. His name is Sarkis, he tells her, and he is an immortal warrior trapped in a prison of enchanted steel.
 
Sarkis is sworn to protect whoever wields the sword, and for Halla—a most unusual wielder—he finds himself fending off not grand armies and deadly assassins but instead everything from kindly-seeming bandits to roving inquisitors to her own in-laws. But as Halla and Sarkis grow closer, they overlook the biggest threat of all—the sword itself.