From the non-existent perspective(Atheistic, Agnostic, some religion that is not Judaism or Christianity) you simply have an authority figure and a rebel. If you're using the description of satan within the texts that appear in both the biblical old testament and Talmud, (Which does NOT go hand-in-hand with demanding his existence. At this point, it's the analysis of a literary character.) Now for the arguments for the presence of satan's morality. 1, Katsuni's, "That God was a jerk, and banished him from paradise because he wouldn't kneel without reason." Actually, that doesn't cover all the source material. For one, the previous point that, "An ENTP[Satan] would look at that and demand a reason to worship, proof of awesomeness, and would take things very poorly if they were told to sit down and shut up." Doesn't fly due to the fact that satan's rebellion was based on a combination of arrogance, and envy. "I will ascend above the tops of the clouds; I will make myself like the Most High."-Lucifer, Isaiah 14:14. Given context, "make myself like" implies envy as opposed to rebellion based on a lack of proof given. Seeing as how envy requires acknowledgment of what the envied possesses, I don't currently see how that argument flies. Furthermore, if you're going to try to argue that there's more aside from the OT and Talmudic sources, then honestly speaking you're acknowledging the existence of Satan, and therefore God. At which point, you only have Judeo-Christian texts, thus creating a contradiction.
Also, Oberon, this topic doesn't demand Satan's existence. See: Typing of Anime and Video-Game characters.