Devil Temptation, commonly known as the Temptation or Madness is a Demonic spell released apon the Human Realm by Mundus' Seven Deadly Sins. The Temptaion causes average humans to choose the path of the Demon and worship Mundus in order to gain power beyond their comprehension while forsaking themselves from the afterlife.
The Temptaion was released by the Seven Deadly Sins when they were the only Demons remaining in the human realm. They split themselves in order to create a special Devil Arm that is completley unknown to the world; that Devil Arm releases the madness upon the world. The Madness twists people's morality into augmenting the seven deadly sins within them; forcing them to choose the path of a demon. The process can take a lifetime to become effective or several days depending on the victim's morality. The Temptation can only be counteracted by Angels themselves through The Orders Device-The Cross.