bilqees momath

She did know actually. She figured it out when she did one of her monologues

Cheng cheng came to this universe before taner. He was there for a few month and its stated that he lost his memories when he first arrived (memories of the matriarch world). Which we know is because he is cheng cheng and not mo lian cheng. Mlc is dead. The soul bead some how created a memory block on cc so he act differently and thinks he is mlc. All the knowledge he know is what he learnt in his first few months after he awoke. Hope this makes sense to you