I found someone's theory! I don't know if it's a cliffhanger butttt it's interesting so spoilerish below for the ones who want it!!
So from what I heard, she really is a character in the book. The girl was killed (I don't remember the reason) before Aseph could meet her that's why she wasn't in the story and also the reason why Aseph fell into obsession with her sister, because her aura was pretty similar to his fated pair, who is Zay. My theory is that, the reason why Zay was so broken hearted about Aseph's tragedy is because he is her soulmate and her soul feels devastated to see her fated pair in despair.
Thank you to the person who said this it makes so much sense!!! I wonder when the new chapters will be uploaded!
MAIMAI IS A REAL #GIRLBOSS