Board Thread:General Discussion/@comment-5479290-20151110231351/@comment-27094327-20151111072841

I doubt that just any item would work. The dagger was a substantial part of the self-same Grail that gave Nimue her powers. It would make sense that it retained a link to her. If a reasonably powerful magician can, with a wave of their hand, bind someone else to any item--it's just messy.