This helpful dialogue about the Dreamstone's origin helps us to understand:
DIANA: Dechalafrea Ero.
STEVE: What’s that?
DIANA: A very bad God. The God of Lies, Dolos, Mendacius, Duke of Deception. He’s been called by many names. But if he’s the one who empowered that stone, there has to be a trick.
BARBARA: What do lies have to do with granting wishes? It ...