The user input can control the demon most of the way, most of the time! We don't know how to obtain full, absolute, guaranteed control over a demon while still

The user input can control the demon most of the way, most of the time! We don't know how to obtain full, absolute, guaranteed control over a demon while still having a useful demon. Might be impossible. Forbidden knowledge be like that - it's not the best thing if you want your life to be full of certainties. But the demons are very useful. And they're getting more useful still. So we aren't about to stop.