Re: WWYCD: They Walk Through Walls?
This looks like a job for WICCA !
She would be able to determine whether said Villains were really Supernatural Creatures or Mages. If Creatures, she would try to dispell them, with her Master's help, if needed, ASAP. They are casual killers. If some Mage sent them, he or she would find themselves with two new enemies.
If they are Mages, it would be a knock-down, drag-out fight. If Wicca won, she would try to imprison them in a super-dimensional prison where they would never be able to harm anyone again. She has never killed anyone, and as she can travel to a dimension where a murdered person is still alive, and the killers counterparts would exist there too, simply killing them in one time and place might not solve the problem.