Rancid Magic

Rancid Magic (朽壊の魔法, Kyūkai no Mahō; lit. "Rotting and Crumbling Magic") is a form of Caster Magic utilized by mostly dark-mages' in general. It is classified as an, "illegal" form of magic due to its nature. Rancid Magic utilizes the elements of rot, filth and decay.

Description
Rancid Magic allows one to create, manipulate and transform anything associated with the element of decay, rot and filth; including tainted blood. It gives the user full control over decayed matter and induce objects and beings with its filthy nature which leads to internal infestation thus resulting in painful death. This magic can easily affect one on large scale, essentially killing them in the process. Obviously, all of the spells are either supplementary or offensive, leaving a little to no room for defense. Once could also cause beings and objects to rot and corrode away or simply be affected by the highly toxic miasma given off by the spells. Rancid Magic by definition has no predefined or definite form, it takes the form of anything the caster wishes it to be in order to cause things to suffer and crumble. This type of Magic can cause extreme environmental pollution or even result in an epidemic, depending on the skill of the user.

Trivia

 * Not to be confused with Death Magic.