Demon Names, also known as Arcane Title and Arcane Names, are special names given by Mercurius, more specifically his Sensory, Karl Ernst Krafft. It is possible that more than one person has the same demon name. These Demon Names were created not only as a diploma for the inhumane members of the Obsidian Round Table as users of the Ewigkeit sorcery bestowed on them by their master, but in reality, they are full of frank irony. In essence, it's a straightforward way of singing, "That's the kind of idiot you are."
Those who are entitled to those names suffer the fate of that particular name. For example, Wilhelm Ehrenburg and his mysterious title of Kaziklu Bey. This Arcane Name is not only an apt manifestation of his desire to become an ideal Vampire, but it also means that he shares the shameful fate of his predecessor, Lord Dracula.
Just as Dracula was betrayed and lost his status and his beloved wife as a result, Wilhelm, his successor, is also doomed to mourn. It's the symbol that being his carries the karma and curse of having everything and everyone he wants inevitably slipping through his fingers.
Although Longinus Thirteen members find them unpleasant, most of them use it for themselves and/or call others by their titles for their own reasons: A very easy way to make fun of those they don't like, expressing respect and/or smugness for being sorcerers who have transcended humanity, or a vow to rebel against the curse and karma by conquering them someday.
| Demon Name | Meaning | True Name |
|---|---|---|
| Mephistopheles | The Beguiling Light | Reinhard Heydrich |
| Tubal Cain | Death Eater | |
| Christof Lohengrin | Carrier of God | Valeria Trifa |
| Kaziklu Bey | Lord Impaler | Wilhelm Ehrenburg |
| Valkyria | Maiden of War | Beatrice Waltrud von Kircheisen |
| Leonhard August | Lionheart Blade | Kei Sakurai |
| Sonnenkind | Child of the Sun | Isaak (Eine Sonnenkind) |
| Goëtz von Berlichingen | Arm of Steel | Machina |
| Malleus Maleficarum | Hammer of Witches | Rusalka Schwagerin |
| Samiel Zentaur | Demonic Chaste Gunner | Eleonore von Wittenburg |
| Rot Spinne | Crimson Spider | Unknown |
| Babylon Magdalena | Great Harlot | Riza Brenner |
| Hróðvitnir | The Notorious Wolf | Wolfgang Schreiber |
| Mercurius | The Mercurial King | Karl Ernst Krafft |
| Zarathustra | Principle of the Trascended Man | Ren Fuji |
| Georgius | He who controls the wolves | Shirou Yusa |