Dungeon Erosion

Dungeon Erosion (迷宮侵蝕編) is the twenty-first volume of the That Time I Got Reincarnated as a Slime Light Novel.

Synopsis
While the loss of Rimuru upsets the Monsters of Tempest, Vega's wicked hand reaches out to invade the Dungeon.

The news of Rimuru's disappearance sends tremors through the Monster Federation. However, unlike before, the executives now quickly regain their composure as they are convinced that Rimuru is still alive. It would be no laughing matter if the country was gone when Rimuru returned. For now, they must deal with the problem at hand. Thinking so, Benimaru concentrates on the angel army led by Dino that has invaded the dungeon. Among them, Vega's Erosion Skill has a troublesome performance. In this difficult situation, two jet-black figures stand in front of the enemy.

Chapters

 * Prologue: Decisive Moment (決意の時)
 * Chapter 1: Dying Region (滅びゆく部)
 * Intermission: The Insect Lord (蟲の王)
 * Chapter 2: Dungeon Erosion (迷宮侵蝕)
 * Chapter 3: Parent and Child (親と子)
 * Chapter 4: Beyond of the Delusion (妄執の彼方)
 * Epilogue: The Point of End (終焉の先)

Adaptations
This volume was adapted into the following material:

Manga
 * Information to be added.

Anime
 * Information to be added.

Afterword
"Information to be added."

- TBA