Battle of Ash and Evil

In 500 BA, the Ashborn gods won the fight against evil and won. They fought back and sealed away all of the evil into what would be known as the Soot Circles - a land beneath The Ash where most evil creatures are chained in pentagram-esque circles of soot. Every once in a while, one will escape or be summoned out of its circle. That's how baddies show up in the world.