Ars Magica: Realms of Power - The Infernal
Ars Magica Sourcebook, Hardcover by Atlas Games
Demons work to corrupt all the people of Mythic Europe. They take on attractive forms, but ultimately they seek to drag all of humanity down into damnation with them. No matter the nation, the creed, or the race, they are the true enemy. The thirteen chapters of this book cover all of the manifestations of the forces of the Evil One.