The Nature of the Unholy Codex
The Unholy Codex is older than time itself. It is said that it was created in the same breath that the Great Maker exhaled that formed the multiverse. Every immortal being that has ever existed is tied inextricably to the Codex, which is thought to represent the seed of corruption that sparked the dichotomy between good and evil in the multiverse.
The Codex is a book of unspeakable power. It is an index of all the immortals of the multiverse, an ever-growing, ever-expanding list of the most powerful beings throughout the planes. Its pages alter with the birth and death of these beings. It contains the appropriate ritual to summon every immortal creature in existence, even the most powerful and clandestine gods, whose names and influence are unknown to this world. Those who can decipher its secret language can summon these beings at will, though they exert no control over them and may suffer terrible retribution for their actions.
However, it has been theorized by ancient dragonborn scholars from Arkhosia that certain rituals within the Codex, when used in conjunction with others, can be used to create a formula to manipulate the wills of these divine beings. In fact, a true understanding of the complex relationships between these rituals can lead one to destroy, create or combine the essences of any divine being listed in the Codex.
The History of the Unholy Codex
The Codex appears through the eons in all parts of the multiverse, constantly lost and found by all manner of creatures. Terrible wars have been fought over it, empires overthrown, families sundered, loves destroyed. It is thought that the Blood War between the baatezu and tanari'i began over the Codex, while the great god Heironeus perished upon the slightest contact with it in a great white blast that annihilated an entire plane.
Within the world of Annoril, the Codex appeared in this eon just over a century ago. It was brought forth from a dark place in the world by a deranged man named Caiaphas, a maniac who supposedly delved too deep into the Great Divide and was driven mad by what he saw there. Caiaphas was hunted and wooed by angels, devils, primordials, all in an effort to capture the Codex. Though insane, he was still wily, and he managed to escape every encounter with these creatures and fled far to the west. What happened is unknown to him, but the Codex went with him and is now lost from history.
Fragments of Arkhosian lore exist on the Codex, hinting that the dragonborn had studied the tome extensively and had perhaps even begun to understand the mathematical relationships between the various rituals. At the very least, evidence certainly exists indicating the Arkhosians had deciphered its encrypted language.
A letter recently discovered by the PCs in the lair of Lava Bite revealed that a cultist by the name of Black Wyrmsergeant Golbagh had discovered the location of the Codex within the ruins of the palace of Zartael the Mad deep in the Holoroon Marsh.
At the Second Grand Council, the Five Dragons of the Broken Kingdom convinced Sallinous Raemyr of the importance of retrieving the Codex after a delegation from Mithrandein warned that evil agents from the Feywild were also in search of the tome.