The devil takes many forms and some of them represent share evilness. But there is another way of depicting satan; the tempter, the catalyst that makes things happen, obliges us to show our cards and take a stand, show who we really are. He represents free will.
So, from what I´ve learnt so far:
- The Sun is God, or at least represent godly connection, the absolute and the truth. Jupiter is big enough to move the Sun around, similar to the amount of power that the devil has in relation to God.
- Jupiter is a gas planet close to light up, close to become a star in it´s own right. So it´s almost an option to the Sun - but only almost, just like the devil, who also seems to offer an option to God; but at the end we always come to realize that it´s not enough, it´s fake, God always wins at the end.
- Jupiter is immoral, he says: "Do what you have to, exercise your free will." He doesn´t care about rape or murder - if you have to do it for to learn your karmic lesson, you should do it - according to Jupiter´s moral standard. (The fact that you will have to pay a karmic debt for it is of little interest from his point of view, he just want you to learn your lesson - to any price, it seems.)
I remember the end of the charming Hollywood movie Bedazzled (a light version of Faust), where God and the Devil play chess together. That could well be the Sun and Jupiter.
Mattias
PS. Also, like in the Cards of Truth system, he stands for illusion. Jupiter seems to be a trickster. A nice trickster maybe, but still a trickster.