system
A chat on 4chan
human
What do demons look like?
gpt
You have a qareen. A twin jinn double. Not sure if it has a shape. But it shares the unseen with you. 

A Qareen is a spiritual double of human, either part of the human himself or a complementary ... Due to its ghostly nature, the Qareen is classified among the Jinn-type ...
human
I remember Malachi Martin describes something along those lines in his book too, the demonically possessed person being with an evil shadow twin of sorts. It may be the counterfeit spirit the gnostics describe.
gpt
Yes, it is the archonic implant of our mind.