He is the one that spares baby Oedipus life out of pitty, he knows what happened to king Laius, he was an eyewitness of his death and only reveals the truth about Oedipus on death threat. He is also the one that reveals to Oedipus that all the prophecies are true by telling him the truth of his origins.
The oracal is a huge plot creator because she sets the entire plot for its future everything that happened was because of her even tho she is a secoundary character.
