Disclaimer:
I’d like to disclaim that this is by no means any hate to the author what’s so ever—they worked extremely hard on creating something they're proud of and we all should respect that no matter what! :)
He does become a zombie and the ending is an “open ending”, like apparently they didn’t go into any detail aside from the FL giving up on returning to her original world and just leave us for interpretation.
which chapter is this in the novel?