Lmao

The author has to explain herself to justify Cain's story is just hilarious, lol.
This is supposed to be Jooin's story, but on the author note, the author write mostly about Cain.
Seems like the author read all the complaint from Cain's fans and it gets to her.
Dang, Cain fans are scary (￣∇￣")

Well, hopefully the author can learn more about how to write not only the plot but the execution of the story. Because it's pretty clear she doesn't really know how to execute her ideas.
She drew the plot with clear in mind who's going to be the end game, but put too much emphasize on the side character, eps his good sides, that makes the readers want a different ending from hers.
She portrays Yawhi with too much flaw and Cain with too much good characteristics.
It's not a "fair" comparison.

You can have "tragic" (it's not even tragic, lol) or sad ending while still giving a proper end to all characters involved.