Just looking at this beautiful magic dagger made me think of the dagger that Professor Murdoch showed Merrill in the episode "The Bleeding Frenzy". Could this also mean that the Professor has a deeper knowledge of the occult?
The "magic dagger" used in Tibetan tantric rituals is called a phurpa, it is used to destroy evil spirits and  physical obstacles.
The phurpa is used as a multipurpose instrument in that you can use it to bind evil spirits by stabbing and binding the evil spirit to the ground .The form of the phurpa suggests  that it resembles a  tent peg with its three-sided blades these pegs are used to fasten the rope stays  of tents.
The triple blades stand for the three root poisons ignorance, desire, and hatred and the need to control these three elements in the past, present and future. The Head shows its ferocious activity and the triangular form  represents fire.
When using the phurpa for a meditation ritual, the sadhana of the phurpa is chanted to draw evil spirits  into the phurpa. After achieving this it is essential  that the will power, and concentration  is controlled to succeed in defeating the evil spirits. Because it might become necessary to in visualize impaling the evil spirits to conquer them.

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