Shaal, also known as the Goat of Scythes, is a (previously thought to be low level) dark entity summoned by The Sorcerer in a deal. It is later revealed that he commands a legion of demons, second only to the mysterious Trafalnor.
They find him in a small out of the way temple, after chasing what they believe to be the assassin hired to kill the king. He manifests first as a dark shadow with goat's horns, and then a cloaked man with a band of dark metal and a scythe.
He taunts Aten, having stolen his sister from the village in Cullio that they live in, having waited for her to step outside the protection of the Silver Apple Tree.
As he dies, he gives Aten a warning that the darkness is coming and will soon envelop all of Caelum. He dies laughing, announcing that this is only the beginning.