Phat
My definition of Satan is that that is just a name for literary purposes to encompass the evil ideas and notions that we have.
For our purposes here we can still use that name.
God created Satan for a reason. God has shown where He uses Satan to accomplish certain ends. This Satan then is good in the hands of God.
Therefore Satan is good.
This is in keeping with the idea that everything that God has made is Perfect, even Satan.
After death we become part of the Godhead. In full contact with all the knowledge that God possesses. We will have free will and obviously use it correctly.
Regards
DL