Looking at the devil-faced book cover, Jacob felt skeptical and somewhat apprehensive. Towards the end, Immortika revealed the reason for Elia's attraction to him, and it was all because of this book, which Immortika had never bothered to comment on before.
It turned out that this book is called the Liber Chaotica, and apparently, it contained the inheritance of a mysterious being who was proficient in the Absolute Curses of Wrath and Pride!
Although Immortika didn't reveal the mysterious being, it was quite clear to Jacob that whoever it was, it was extremely powerful because this Liber Chaotica's rank was not revealed to Jacob because he wasn't privy to this information yet, which shocked Jacob to the core.