Here is The devil king is bored chapter 34b. This is a special episode about the manhwa’s background settings.
There are upto chapter 39 of Devil king is bored on Mangahere.
http://www.mangahere.co/manga/the_devil_king_is_bored/
But bakaupdate says that only chapters upto 29 is scanlated. So they haven’t updated to most recent chapters yet.
Here is a download link because Mangahere updates slowly.
http://www.mediafire.com/file/9d0wu69hpdtspmo/devil_34b.zip