The Demon King is the unseen antagonist of the KonoSuba series, and is currently engaged in a war with Belzerg, and by extension the world at large. He resides in his castle, which has a powerful barrier protecting it, even being able to withstand the power of the Crimson Demon Clan. He is rumored to be incredibly powerful and ruthless, however, it seems that many of the negative rumors may be baseless accusations by the inhabitants ofAlcanretia, and according to the Prime Minister of Elroad he is a very sophisticated and reasonable person. It is also mentioned by Kazuma that one of the main reasons the Demon King is at war with Belzerg is due to the antagonization by the Crimson Demon Clan and the Axis Order. However, this may possibly be a joke.