You were a gift from Mother Miranda to Karl - something to keep him at bay. And he had grown to love you very much. You failed the Cadou experiment that was “almost perfect”.

To him, you were his in a way, and he was trying his best to keep you safe in his factory - he didn’t want to lose you.

Karl had left you to stay the night at the Dimitrescu's. Why didn't he know better? Alcina's daughters thought you were a toy, after all.