As lawyers are fond of saying...
"Put the case" that we are discussing a hyper intelligent, deceptive being whose primary motivation in envy and emulation of God. Being past redemption himself, he wants to rob as many people as he can of the chance of salvation through the means God has provided.
What might he do to attempt this deception?
If people even on this forum might come on it with multiple apparently unrelated identities in order to creat and perpetuate a narrative line to support their objectives, why do we imagine that Satan, infinitely more sophisticated and malevolent than the nastiest internet troll, might not do the same? Would he be likely to be cloddish and pedestrian in his intrigues or a more accomplished liar than that?
Paul seems to express this view in 2 Corinthians 11:-
13For such
are false apostles, deceitful workers, transforming themselves into the apostles of Christ.
14And no marvel; for
Satan himself is transformed into an angel of light. 15Therefore
it is no great thing if his ministers also be transformed as the ministers of righteousness; whose end shall be according to their works.
So - why is the occult so keen on dualism? Why all the black and white magic, the dark and light sides of the "force"? For those who know who the "Hero with a Thousand Faces" really is, the answer is obvious.