Ok, thanks for the context Tashuna. It was, "she's a loose end". A "loose end" is an "unresolved problem" or "something left unfinisted". It's like a rope that has it's end loose, instead of being tied in a knot. So it means that this witch was an unrsolved problem for them, and he "likes his problems resolved". It's kind of a play on words.

Tashuna, It's hard to say without the context. Could you post the sentences before and after that one? I can tell you that "tied up" can mean "bound", like bound with rope or sting. It can also mean "busy", but it all depends on the context.

That depends what he or she likes tied up. Perhaps she likes her sex tied up. That means she likes to be tied up when having sex.