Then it's choose your own definition, and at the core, meaningless however you slice it, because according to that view it's a mix of truth and myth and each person is left to make of it what they will. That's basically protestantism which is the same self interpretation of scripture. "Dah holy spirit guided me". The self appointed bishop.
He's not a consistent figure. He's a deceiver, and a liar, so that is his natural M.O, so he can appear in a variety of forms. There's no scriptural mugshot of his form-appearance, only his behavior.
Correct on one hand, there is no official "satanism", it's all interpolated from scripture in the same self guided way protestantism is, minus Christ. I would assume some of the more devout practicioners (as well as exorcists) have received many personal revelations about him outside biblical and related sources. Some satanists believe in Christ but just reject those teachings. Even the demons believe in Christ.
But it's also inaccurate on the other hand, because plenty of heretical faith brands include Jesus but are satanic. Protestantism is a satanic heresy that includes Jesus but twists theology to exclude the body and blood of Christ in the mystical supper, the very core of the faith. "Maitreya" in new age religion is a christ figure but is a false Christ. One of the commonalities throughout scripture is the counterfeiting of genuine faith. This is why we have hundreds, thousands, of counterfeit denominations. In my view, anything claiming Christ outside orthodoxy is satanic in origin. The best way to sell lies is to mix some truth with it. Our own MSM basically uses that satanic MO on a daily basis and people accept it as gospel. Where do you think they learned it from?