Magic items are weapons used by magicians. Only magicians are capable of using magic items and even then it depends on their compatibility. As stated by Junichiro, he doesn't have a strong enough output to efficiently work a gun, though Yumikage can use them with ease. Magic items are typically used to fight vampires, though they have been known to have dangerous effect on humans. A drawback for magicians using magic is that it will eventually take a toll on their spirit. Symptoms of a magicians reaching their limit include being unable to recognize the faces of people around them, hallucinations of 'faceless people coming after them' and the person's spirit will return to that of a child. For magicians like Tsurugi, it appears to be an agonizing experience.