I see, so demons are in fact a society, which means they need a demon lord for protection (from the humans), meanwhile demon lord get a strong army at his beck and call. This is really another reason their world need a demon lord.
@uvarine @Ruleofpro @Miranox I enjoy both but Overlord is definitely the story about Ainz, and Ainz inside is just a clueless normal otaku guy, thats why his decision is kinda sometimes not fitting and annoying, for me at last (well its become the joke in the series).
Meanwhile this series has original dweller reincarnated, so I expect it to not have any stupid decision, but this series reminded me about Maou Mayuu Yuusha (anyone already read it?) and I think this series in the future will take some part of that.
Well, at this point there will be rarely any original series, I mean many about elf in many series is referenced on Tolkien novels, meanwhile a story about hero and demon lord is usually referenced from D&D (board one), vampire? well it get their reference from Nosferatu & Dracula (a black&white film you can search it on youtube, and a novel), and youkai series (like Inuyasha) take their reference from 100 ghost stories (a very old Japanese ghost stories compilation, dated back to Heian era).