Seventh Holy Scripture

The Seventh Holy Scripture is a weapon of the Catholic Church, considered one of the strongest, but as it needs an incredibly strong wielder, it is not often used. It is both a physical and conceptual weapon, meaning those undead and vampiric cannot heal from the wounds it causes immediately.

History
Originally made from a unicorn horn and the soul of a young woman, so as to combine the nature spirit of the unicorn with the human spirit of the young woman, who gave her life willingly in order to achieve this.

Current User
Currently used by Ciel, the Seventh Holy Scripture has a large mechanical weapon form, including a pile bunker. Ciel has 'customized' the weapon, adding four dots to it to make it look more industrial.

Spirit
The spirit of the Seventh Holy Scripture was originally only referred to as 'Seven', even by Ciel, but after being tossed into a river and found by Inui Arihiko she was dubbed Nanako, Nana being Japanese for 'seven' and -ko being a feminine name ending. She complains a lot about her current master and how she is treated, but she is still fairly loyal to her, as she has never had a master strong enough to make her appear in spirit form. It seems that only those who have formed a contract via blood can see and hear her at times, yet at other times others have indeed witnessed her, making this unclear.