I *think* I remember that or something similar. I swore it was something like he confined her somewhere where no one knew where she was or was inaccessible. He might've chained her up, but he also took away her vision, hearing, and voice. I think.
Basically, she couldn't do anything at all. He wanted to break her. If I remember right, he wanted her to be like a dog?
The curse would only lift when he visited her.
Her only escape was through the dreams. Eventually, her father encounters her in a dream And he explained he was a dream demon. Her mother wasn't a demon.
Then they collaborate to save her. When ML goes to visit her again, she is gone, and he goes nuts.
That's what I remember, but I could be mistaken.

All I know is that I'm lost