The Jura Tempest Federation, with Rimuru as its leader, has formed an alliance with the Armed Nation of Dwargon. Just as Rimuru thinks there are only peaceful days ahead, he senses an enormous mass of magical power heading straight for his location at an incredible speed. When the smoke from its collision with the ground clears, standing in its place is a humanoid figure. She is the Demon Mord Milim, the one and only Dragonoid and the one bearing the nickname "Destroyer." Ranga, Benimaru, and the others who face her are quickly overwhelmed by her power.

Phobio can't restrain his anger toward Milim. He finds himself faced with Footman and Tear, two masked members of the Moderate Harlequin Alliance, who suggest that he become a Demon Lord to take revenge on Milim. They tell him that he can accomplish this using the power of Charybdis. Meanwhile, the Jura Tempest Federation sends Youm out on a journey to make the world believe he was the champion who defeated the Orc Lord.