Kisaki

After 17 bizarre possessions—including a tree, a salt shaker, and a jellyfish—she finally ends up in the body of a beastman. But this life is no easier: a powerless albino mermaid, a spy marked for death, and a background extra in a villainous household. Just as she's ready to give up, the most feared villain offers her a place in his family—as his daughter-in-law. Can she survive among monsters without losing herself again?

The magic tree that grows in Tate's hometown always existed as a safeguard from evil entities and creatures. That is, until Tate came across a runaway slave and began nursing him back to health. Suddenly, this strange man's presence causes a chain of even stranger events to occur, including an attack on the town's magic tree!