This book title Swordheart
books by T. Kingfisher

Halla is a housekeeper who has suddenly inherited her great-uncle's estate... and, unfortunately, his relatives. Sarkis is an immortal swordsman trapped in a prison of enchanted steel. When Halla draws the sword that imprisons him, Sarkis finds himself attempting to defend his new wielder against everything from bandits and roving inquisitors to her own in-laws... and the sword itself may prove to be the greatest threat of all.
The book’s writing style prioritizes readability, making it easy to stay immersed for extended periods. Clear sentence structure and logical flow help maintain momentum. This accessibility is one of the book’s key strengths.
The pacing of the book reflects a careful consideration of reader engagement. Moments of intensity are balanced with quieter scenes that provide context and reflection. This rhythm keeps the story dynamic without becoming overwhelming.