Responses
Yes and no, depends on how you look at it. It's definitely bittersweet tho, but there's a sequel to the main story named Sanctify: Lost paradise, all chapters are posted as one, so it's pretty long, still bittersweet but gives you more closure.
Overall the story is really good and the ending itself is perfectly fitting.

Does this have a sad ending? I do not read anything with sad endings so tell meee