Season: 1

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.

Post-war arrangements following the battle with the Orcs have begun. At the meeting, Rimuru reveals that he made a promise with the Orc Disaster, Geld, to take all of the Orcs' sins upon himself. When the Ogres and Lizardmen hear this…

Rimuru and his Goblin riders set out for the marshlands to finalize their alliance with the Lizardmen. On the way, they save a Lizardman who'd been attacked by the Orcs. The victim turns out to be Gabiru's younger sister, who reveals that Gabiru led an insurrection and left to fight the Orc Lord without waiting for the alliance. She also pleads with Rimuru to save Gabiru and the rest of her clan. Meanwhile, Gabiru faces the massive Orc army and is shocked when he witnesses the power of their unique skill, Starved.

The Orc army, led by the Orc Lord, continues its conquest throughout the Great Forest of Jura. The crisis has spurred Treyni of the Dryads, the caretakers of the forest, to take action. She has had her eye on Rimuru after noticing his rise to prominence in the forest, and she wants Rimuru to defeat the Orc Lord.