meh in a magical world slavery could be on a whole 'nother level. magical slavery would ensure she still gets to live while guaranteeing that she won't be a further liability to the MC. Though I will say that the way it was delivered was poorly done, they could have had a special name for it or something like call it being magically bound to lento where you would actually have to think about the meaning a little bit.
I mean death is too dramatic and doesn't actually guarantee anything especially if they decide to do it at the cost of their life, in which case they can do it in a most damaging way, where if they were a slave it would be up to him to decide an appropriate punishment and he could also get information on what info was released.
Then again the fact that they gotta go to another country to do all this... does kind of defeat the point... in fact I'd say that fact makes it more problematic than its worth.
I mean death is too dramatic and doesn't actually guarantee anything especially if they decide to do it at the cost of their life, in which case they can do it in a most damaging way, where if they were a slave it would be up to him to decide an appropriate punishment and he could also get information on what info was released.
Then again the fact that they gotta go to another country to do all this... does kind of defeat the point... in fact I'd say that fact makes it more problematic than its worth.