According to Mango TV, in The Devil's Law, the true identity of the goddess of light is Semel Rowling, Dewey's great-grandmother and a great astrologer.
Semel once fell in love with the seventh earl of Rowling's family, which led to her being sealed by the goddess of light. Angry Semel betrayed the goddess of light. On the other hand, the magic teacher Gandalf also has a deep love for Semel.
So it can be said that the goddess of light (Semel) once fell in love with the seventh earl of Rowling's family, while Gandalf liked the goddess of light. These complicated emotional entanglements add more depth and connotation to the story of witchcraft.