If the next A Court of Thorns and Roses book is about Elain as everyone suspects, then I really hope it confirms one fan theory about her. Elain, to this point, has been the most mysterious Archeron sister, not because she’s inherently a mysterious character, but because she hasn’t been as well-developed as Nesta and Cassian or Feyre and Rhysand. Whether I like it or not, Sarah J. Maas’ habit is to focus almost exclusively on a few characters in each book and leave the supporting characters less well-developed until the focus is on them. It’s created a problem with A Court of Thorns and Roses‘ stakes and characterization.

https://screenrant.com/court-thorns-roses-next-book-elain-theory-fae-prison-mountain/