Can you show me how the Satan of Judaism differs from the Satan of Christianity? I would be very interested in learning that.
The topics of angels, demons, and the afterlife are more esoteric in Judaism than they are in chrstianity. I will give you the short version, to the best of my ability, but you are better off asking an Orthodox Jewish FReeper.
The Satan is merely an angel of G-d doing his assigned job(s). The primary job is accusing people before G-d in Heaven, though he has also traditionally identified with the angel of death the evil inclination, and the angel of the nation of 'Edom. At any rate, angels do their jobs. They do not rebel, whether this is because they lack free will or because their free will is so perfectly attuned to that of G-d that they never swerve from it. The chrstian "satan" as an evil counterpart of G-d does not exist in Judaism, since G-d has no counterpart of any kind--evil or otherwise.
You might want to see this.
Judaism and chrstianity are very different. Judaism is NOT just chrstianity waiting for J*sus to come. Chrstians get their chrstianity from the "new testament" which is then projected onto the Hebrew Bible.
How do you square that with Isaiah 14:12-15?
BTW, as powerful as Satan is (aren't all angels powerful?) he is not a counterpart of God because he is not infinitely powerful.