Vivian didn't spend money on this book either, but took it directly from Grace's shelf to borrow it for some time.
Grace owns a library of her own, with a vast collection of books in various fields, it can be considered a treasure trove.
As her student, Vivian naturally can borrow some basic books.
After Duke got this book, he found it to be a sky-blue book, much thinner than expected, even thinner than "Magic Basic Theory".
He opened the book to discover that it contained a universe within.
This is a book that needs to be read with Spiritual Power, all the information is carried by Spiritual Power, without using words.
But this also indicates that the book contains a large amount of information.
Not using words is mostly because if it were recorded in words, the content would be extremely long.
When Duke first started reading this book, he felt an overwhelming amount of information.
