Former fiance to Hannah, he witnessed her murder at the hands of a Wraith and was forever scarred by the experience. Over the years that followed, jack poured himself into becoming a Hunter and vowed revenge for his dead fiance. The more he learned about the terrible monsters that lived in the world, the more he realized they must all be destroyed.
Upon encountering the Reaper/Angel duo, Jack revealed his powerful arsenal of magical artifacts. These artifacts were able to even repel the two of them and Jack gave no indication as to how he came about these items.