Tempest is preparing a feast in celebration of Rimuru's return home. Then a newcomer, the majin Myulan, arrives to scope out Tempest on the Demon Lord Clayman's orders, having joined up with Youm's crew as their military advisor in order to enter the nation. Upon arriving, she's surprised to see what a strong nation it is, but continues to talk with its citizens to learn more. Meanwhile, the king of Falmuth, who sees Tempest as a nuisance, conspires with the Western Holy Church in a plot to invade the monster nation.

The battle for revenge has begun. Benimaru and his trusted companions carry out their respective missions, while Hakurou and his party face Shogo and Kyoya once again. And Rimuru's fury rains down upon the army from Falmuth.

Rimuru succeeds in collecting enough souls to carry out his plan to evolve, and the Harvest Festival begins. But he's suddenly overcome by intense sleepiness at the same time, so he summons a demon to stop Razen, the one target who escaped alive. Then, upon returning to Tempest after successfully becoming a Demon Lord, Rimuru sets about attempting to revive Shion and the rest of the fallen. Through Raphael, the evolved form of Great Sage, the Secret Arts of Spirit Resurrection and Revival of the Dead are activated...

Rimuru has returned to Jura after having attended Walpurgis. Diablo informs Rimuru of his mission to deal with the Kingdom of Falmuth. Having presented the kingdom with three options at a resolution, the clock on the week for their answer ticks down.