So I've been playing imperial city and I've become extremely fed up with forever cloaking magicka night blades but I like all the skills I currently use on my bar and don't want to swap one out for flare. So I'm looking to use detection pots if someone could explain to me exactly how they work like how long do they last? At what range will it detect? If I realize I'm fighting a NB can I cast it before he cloaks and will it keep him out?