Decay Magic

Decay Magic is a Caster Magic that creates a substance that is able to make things rot and decay upon contact. It is also a type of Lost Magic, it was said to be wielded by this Mage a long time ago, unfortunately, this Mage abused this power. He used the magic to his own pleasure which included criminal things, so he was executed and the Magic was supposedly destroyed.

But, the Mage that created this Magic also wrote it down in a secret book that he hid in a ruin that was underground, he caved in the ruin and hundreds of years in the future, Ryuk Levy with his Earth Magic found this book and the Dangerous Magic the Mage made.