Liber Mors

Summary
Liber Mors is a spell that is cast on a book, corrupting it and causing whoever touches the book to have their hand fall off. The duration of the corruption of the book and the faster and more powerful the process is depends on the strength of the magical values of the book, with the duration getting lower and the process becoming faster as the book gets stronger.

Magical Value is determined by the influence on magical history as well as the magical potential of the book. For example, a normal book would be weaker than a basic spellbook, which would be weaker than The Bible, which would be weaker than an advanced spellbook and so on.

It is the weaker form of Liber Magis Mortiferum.

Uses
Liber Mors is a spell used almost exclusively in wars between mages, where one mage would corrupt another's spellbook in an attempt to cripple them. Merlin used this spell countless times against his various adversaries, especially against Rex Malibu, who was unable to use magic without a spellbook.