The Ruler of Conspiracy picks up shortly (a few weeks) after the end of the previous book. For anime viewers, this book takes place just after the third season ended. This book focuses almost entirely on Ainz, which was refreshing. As Overlord as progressed, Ainz has received less and less facetime despite being the main protagonist. While it is nice to see other characters as more than background decorations, too much time was being taken away from Ainz to do so. The Ruler of Conspiracy focuses primarily on Nazarick’s efforts on establishing their new nation as a recognized world power.
Having been a salaryman in his previous life, Ainz takes a corporate mindset towards running his country. His thought process heavily involves evaluating resources as well as losses/gains. While his minions have no issue using unethical tactics or direct military force, Ainz puzzles out (relatively) peaceful solutions. Or stumbles into them. Since most The Ruler of Conspiracy is from Ainz’s POV, readers are reminded that he is a normal guy. He commands great military power but intellectually he is fairly average. Most of his opponents do overestimate his intellect and trip themselves up, assuming coincidences were actually brilliant tactical maneuvers.
Perhaps due to his experience as a businessman, Ainz is a master of “fake it til you make it”. His magical power impresses the heck out of people. As does his unconventional use of that magic. When other rulers observe him using monster minions powerful enough to single-handedly destroy countries as guards and manual labor, they are more than a little shocked. Due to his power and influence, everyone around Ainz makes a lot of assumptions. And once aware of those assumptions, Ainz just rolls with it. “Yes, that was my plan all along!” No one has the gall to call him out and realize he is full of baloney.
The plot in this volume is two-fold. One part deals with Ainz establishing diplomatic relations with the Empire. The other deals with Albedo doing the same thing in the Kingdom. Inadvertently, both these actions also affect the Sorcerer Kingdom’s relationship with the Theocracy, the third nearby nation. The Ruler of Conspiracy also starts to mention other nations that are not in the immediate area more heavily. The book mentions there is another nation Demiurge is dealing with while this book ends with Ainz preparing to leave for another nation entirely. It seems that as of this volume, Nazarick’s goal of world conquest is truly underway.