Vorpal swords

Vorpal swords (ヴォーパル の 剣, Vu~ōparu no ken) are a type of cursed weapons with different special abilities.

Summary
The "Vorpal sword" term was originally referring to a very sharp sword, who was in use of a unknown man, who with it kill the Jabberwocky and decapitate him. Blade, soaked in blood of the dragon, became a cursed dragon slaying weapon, but made its user drown in insanity. Blade shattered and its user was banished from death, even now wandering around the world.

Many centuries passed and vorpal fragments were finally used by church, and not only, to create a perfect demon slaying weapon series. They created dozens of them and kept in many places.

Vorpal sword is created when a piece of original Vorpal blade is placed within a normal sword. Then, until someone take it into his/her hands, Vorpal will be only a common blade, but when somebody will want to take it as a weapon, it will change, dependent on its user's will. If the user would want to use it for slaying demons, the Vorpal sword will became his "sacred" weapon, but if someone supposedly "bad" (like devil), or with bad intentions, would want to use it, Vorpal will became a full cursed blade. There are a few different examples than those two, but its destiny is always dependent on its user's will.

Because of the Jabberwocky blood, sometimes users can go mad and insane, becoming some sort of fiend or demon, or even be completely erased from existence, with their body destroyed and their soul torn to pieces.

Types
There are a few types, or series, of vorpal swords, independent of its destiny. Those are one of the most recognizable ones:

Black Wraith Series
The most powerful type of Vorpal swords, undergoing only to the original blade. Those swords have rather bigger parts of the original, what makes them closer to the first one in terms of power, but also in terms of its insanity affect. Black Wraith's users are more vulnerable to Jabberwocky blood, sealed within the fragments, than the users of the other series. Sometimes they are turned by their own weapon into demons, or wraiths, hence the name of this series.

Dragon Slayers
Those Vorpal swords are additionally blessed, so they can slay the dragons. However, with that being done, those blades cannot destroy devils or cursed beings anymore. Fortunately, Dragon Slayers swords are using a rather small fragments of the original blade, so users don't have problems with Jabberwocky blood and usually have with them another Vorpal sword, for killing demons. They generally take the regular one as the second weapon.

White Ghost Series
The second most powerful type of those swords, albeit a lot more controlable. The users have in their weapon a sealed soul of a the demon, who regulates a control over the sword. However, those demons can be very aggresive, trying to take over their masters, although if they can become friendly, users have a safer control over their swords.

Regulars
Regular Vorpal swords with pretty small fragments of the original one.

Users

 * Jabberwocky Slayer - Original Vorpal sword

Black Wraith Series

 * Sora Kurogami - Malesvard

Dragon Slayers

 * Laura Bell - Snake Eater

Regulars

 * Laura Bell - Vanitere