The Book of Eibon is one of the many creations of Eibon. It is explained by Noah that BREW and The Book of Eibon are the wisdom of Eibon — essentially Eibon himself. Like BREW, Eibon's book seems to be highly sought after by both Witches and Shibusen — or at least its contents. It is currently in the possession of Noah. The Index is the embodiment of the contents and intelligence of the book as well as the creator and mastermind of Noah.
Externally; the Book of Eibon's composition doesn't differ much from the traditional construction or representation of a typical hardback, in that the entirity of its contents are bound within the confines of a rigid cover, embellished with various "S" shaped designs. However; befitting the true intentions behind the books existence this simple facade belies the extent of the genius of its original creator, who managed to confine an entirely seperate dimension within this grimoire's pages, successfully decieving all observers to what exactly resides in the depths beyond the physical materials that form its exterior.The Index basically represents the Book's intelligence and is the Physical embodiment of it.
The Book of Eibon contains contents regarding the necessary requirements and processes involved in the creation of various dangerous demon tools original devised by Eibon himself. Perhaps unsurprisingly, many of the pages that act as blueprints of the Demon Tools seem to have been taken from the book and scattered throughout the entirity of the world; such extracts are often referred to as "fragments".
- Moral Manipulation Machine: One of the pages of Eibon's Book holds the blueprint for the creation of this insidious machine, which brings down the morals of any victim that is subject to its tortures, helping to incite the first indications of madness. The blueprint was taken by Arachnophobia and evenually used to construct the actual machine, however, the blueprint was eventually taken by Sid during a mission and the machine was subsequently captured by Shibusen after Arachne's defeat.
- BREW: Brew, the tempest, is said to be the most powerful creation of Eibon. It is explained by Noah that BREW and the Book of Eibon function as the wisdom of Eibon — essentially symbolizing Eibon himself. It is currently in the possession of Noah.
- Demon Weapons: Most famously, the Book of Eibon contains blueprints needed to create Demon Weapons. Despite having thought of the idea, Eibon never actually created one. Instead; 800 years before the start of the series, the witch Arachne, following the instructions she found within the book, created a demon weapon by murdering a fellow Witch to use as a sacrifice. Using the witch's soul, which has the power of transformation, Arachne joined together it (the witch soul), an inanimate weapon and a human soul to create a demonic weapon which had the ability to transform from human form to weapon form. Thus, she earned the title of "Mother of all Demon Weapons".
The Seven Chapters
If Arithmetic Magic is used correctly, a portal can be created that allows people to physically enter the world inside the book. Demons or any beings that have been collected by the book are sent into this world.
The world inside the Book of Eibon is inhabited by the creatures that the book had collected along with the Index that acts as a guide and supervisor to anyone who enters the book.
The book is split into seven chapters, each one representing one of the Seven Deadly Sins. The Index states that at the very end of these chapters lie insanity. If one wants to reach the end, they must each briefly struggle with all the Seven Deadly Sins in each chapter. If they waste their time, their souls would be consumed by the sins and they will fall to madness.
The Introduction This acts as a sort of prologue to the seven chapters. There doesn't seem to be much physical matter in this world and it is made up entirely out of long lines of symbols snaking through the air. It is here that anyone who enters the book is met by the Index, who acts as the guide throughout the rest of the book.
Chapter 1: Lust The world inside the chapter of Lust is made up of a large platform surrounded by large curtains. Outside the platform, some ruins can be seen. In this chapter, the people who enter it undergo a drastic transformation as their genders are switched, with each person appearing as a manifestation of everything they find appealing in the opposite sex. The chapter is also inhabited by creatures such as the Succubus that try to seduce people in order to steal their souls. Additionally, the gender change in the individuals is actually carried on even if they have left the chapter. Upon leaving the chapter of Lust, they slowly start to change back to their original gender, but the speed of their transformation depends on their sexual desire. The stronger the sexual desire, the longer it takes to change back.
Chapter 2: Gluttony Unsurprisingly, the chapter of Gluttony is a world filled with an endless mountain of restaurants and food, intending to attract any hapless passerby with their irresistible smell and taste. It also seems to be inhabited by creatures who are actually edible, such as a giant pig (although it will try to eat people as well).
Chapter 3: Envy This is a little different from the previous two chapters in that in Lust and Gluttony, all individuals experience the sin together in a group. However, in Envy, each person is separated into their own world that is manifested out of their envy. The inhabitants of this chapter wear faces with crooked, vaguely hairlip-like grins and beady white eyes that mock and belittle the one who enters it.
Chapter 4: Wrath The world in this chapter has a volcanic setting littered with old ruins and clouds of ash overhead. The red color of the molten lava that flows in this chapter stimulates the anger of those who enter, making even notably calm people irritable. The annoying Holy Sword Excalibur is contained in this chapter, possibly as a hostage, making the experience all the more excruciating.
Chapter 5: Pride This chapter features an elaborate palace of Arabian or Indian design, looking a lot like the Taj Mahal. The atmosphere is much more peaceful than the chapter Wrath, which helps to soothe the anger of anyone who enters this chapter from the preceding one. However, Excalibur does end up following, and offers his power to allow those journeying through the book to skip to the end, something they contemplate with their inflated pride.
Chapter 6: Sloth Countless beds and chairs logically make up this chapter, tempting those who enter it not only to sit and rest, but also to stymie their ambitions. The panels of the manga itself are much more scarce and disperse, each literal manga page containing no more than three panels in blank white space at a time, with some of the borders appearing torn. There is also no border around the box introducing the title of the chapter, the letters of the title appearing unkempt and each letter varying in size, suggesting the illustrator's own laziness.
Chapter 7: Greed It is is raining money with countless mounds of treasures as well giant Maneki Nekos are found here. This is the last chapter and where our group finds Death the Kid, who appears to have been influenced by madness and is about to do battle with Black Star.
Not surprisingly — as it was created by a legendary sorcerer — the Book of Eibon has displayed various mysterious properties, that allow access to numerous powerful abilities. These powers can be manipulated by another individual other than Eibon himself but to do so requires them to be able to locate specific pages, regarding the individual technique desired.
- Restraints: By placing a particular page above an opponent, magical shackles extend downwards, that are able to restrain and contain even a strong opponent's hands.
- Teleportation: Through the use of a single torn out page from within the book, a person is able to transport themselves instantly to the location of the remaining part of the book. When activated the person is sucked into the page, before it combusts, leaving no remains. After this they are ejected from the rest of the book, and so arrive at their destination.
- Absorption: The book has the ability to trap objects and living beings inside its confines. It appears that this process can hold the captured items for an indefinite amount of time, with little to no means of escape. Only the wielder can allow anything inside the book transverse through to the real world.
- Summoning: By keeping the book open at a particular section, it is capable of summoning worm-like monsters from the confines of this book. These creatures are strong enough to easily overpower Mosquito and pierce his body with their teeth. They are also able to fire a large explosive beam from their mouths, so powerful as to kill Mosquito in his most powerful form with a single blow.
- Noah:The Index was responsible for creating the Noahs a group of Artificial beings to serve it and if a Noah dies a new Noah will be created.They are created thorugh embodiments called Idols.
- The arrangement of the interior contents/chapters of the Book of Eibon shares various similiarities with the structure of the Inferno and Purgatorio featured with Dante's Divine Comedy, due to their equivalent fundamental basis being Christianity's Seven Deadly Sins. The 7 Sins correspond to each chapter in which they become worse as the chapter gets deeper.
- An extract from a page found within the book "Alice's Adventures in Wonderland" is observed in the background of the pannel where the 7 chapters are initially introduced.
- A manuscript of the book, is kept in level 4 of the Shibusen library, which can only be accessed by Death Scythes and their respective senior Meisters.
- The Book of Eibon is based off a similar spellbook with the same name, which appears in the short stories by HP Lovecraft.