With three countries already having fallen to the might of the Arachnea, Grevillea sets her sights on the next target: the Nyrnal Empire, the land of swooping wyverns and a supreme military power. To reach the Nyrnal Empire, Grevillea must first acquire the Eastern Trade Union. Its capital of Khalkha is a hedonistic paradise...but will Grevillea and Emperor Maximillian's clash for supremacy make its streets run red with blood? The Arachnea and the Empire, the last two great powers on the continent, wage war for the right to rule! With Grevillea's secrets dragged out into the light, the story hurtles toward its climax!

Our protagonist is a college student who enjoys playing as the evil-aligned faction Arachnea in her favorite real-time strategy game. One day, she finds herself in a world similar to the one in the game; additionally, her body is now that of a fourteen-year-old girl. While things are a bit different from how they were in the game, one element has remained the same: she is the leader of the Arachnea. The insects under her control, collectively known as the Swarm, praise her and implore her to lead them to victory.In order to survive, she raises her Swarm and forms friendly relations with the elves of the neighboring forest. But after a slaver traveling through the forest murders one of her Swarm and the nearby kingdom's knights burn down the elven village and massacre its people, she prepares to launch her counterattacks in the name of revenge.However, revenge is merely a pretense for attacking the countries of this world. Her command is masterful and severe, as one who has played the game in real life...

"I admit it. You are the leader." "Thank you, Diablo. I will do everything to answer the trust you've placed in me." As it just so turns out, the former prime minister Noah Gibun is an outsider-a Cross Reverie player who was pulled into this world-just like Diablo! She desperately wants to defeat the Gelmed Empire, but due to their overwhelming power, she has to recruit Diablo and the young Demon Lord Klem. The antisocial Diablo wants no part of this! Will he be able to deal with fighting alongside a party for the first time ever? Will he finally overcome his social anxiety? This is the fourteenth volume of the adventures of an earth-shakingly powerful Demon Lord (or at least someone who acts like one) taking on another world!

"Endeavor in my name. I'll allow it!""Let's go on an adventure then-to the Viridian Cathedral!" MMORPG Cross Reverie's top player, Takuma Sakamoto, is summoned to another world where he's forced to play the part of his in-game character, Demon Lord Diablo! Diablo has successfully saved Faltra in his greatest battle yet, but there's no rest for the weary! A summons arrives from the Kingdom of Lyferia, demanding Diablo make an audience with the king. However, Diablo also learns the wedding ring he gave Rem actually forms a pair with Shera's! Diablo teams up with Faltra's guildmaster, Sylvie, to arrange an official substitute.

Will Diablo be able to conquer the dungeon he himself created?! The High Priest Lumachina has been afflicted with a curse, and Diablo's only way of saving her is by reclaiming an item he once obtained in the game Cross Reverie. His next challenge: a dungeon that has claimed the lives of many brave adventurers... But his confidence isn't misplaced, for it was he who designed that very dungeon! Even when facing off against a supreme dragon, Diablo never falters, just like a true Demon Lord! "Heh, you think yourself a God with a mere level of 140? Don't make me laugh, you overgrown newt!" At the same time, a Fallen heralding the return of the Demon Lord appears in Zircon Tower...?! Will Diablo be able to conquer the dungeon he himself created to retrieve the cure and make it back to defend Zircon Tower in time?!