Vassal Book

The Vassal Book is one of the Eight Vassal Weapons from Glass' World. The person who possess the weapon is called the Book Hero. The book holds a blue gem which can absorb materials and the ability to transform into presumably other book based forms.

The current Book Hero is unknown.

The former Book Hero was Kyo Ethnina.

Trivia

 * In the Web Novel, Marin wielded the Vassal Book.