Defeat the Hero and Save the World!? The Demon King's Dungeon Creator!!

Mana

The magical power that fills the air and living beings. It increases slowly in nature-rich lands and is lost in human civilization.

Dungeon

The designation for monster habitats. It includes not only underground labyrinths but also reclaimed forests and deserts—in essence, territory management.

The Calamity Known as Heroes

Vanguard soldiers who do not fear death have become commonplace. Nature and monsters alike see them merely as resources or obstacles.

Slime Producer

The form mana takes when it gains life. It is the foundation of the ecosystem, absorbing and releasing mana to become sustenance for others. When sufficiently accumulated, it splits, doubling in number within a day.

Goblin Primary Consumer

Small, green-skinned humanoids. Individually weak, but brave in groups. They are viviparous, reproducing quickly and expanding their numbers within days, serving as frontline troops.

Lizardman Main Force

Warriors with tough scales. They wield spears and shields, forming organized defensive lines in groups. They are the core of defense, excelling in balancing reproduction and combat strength.

Demon (Ma'oku) High-tier Predator

An intelligent race with a high level of magical civilization, forming the core of monsters. Reproduction requires a full-day ritual, making their numbers difficult to increase.

Dragon Apex Predator

Breathing fire and soaring through the skies, they are the beings humanity fears most. While their abilities overwhelm others, their strong pride makes them a double-edged sword that threatens the ecosystem.

Summoner

Demonic Girl / Monster Coordinator

Clad in a staff and pointed hat, she is the only one born with the innate knowledge of the secret spell to summon the Demon Lord. Proud of her role and origins, she feels a greater responsibility for the future of the monsters than anyone else. Loyal to the Demon Lord, sharp-tongued towards humanity.

Serious and diligent, intelligent yet maintaining a cheerful tone. She occasionally lets slip profound remarks.

Nurture the Territory

Create terrain and cultivate the ecosystem in occupied territories while increasing monster populations. Adjusting individual numbers through breeding is also a necessary ruling decision.

Repel the Heroes

When the grace period expires, Heroes will invade the dungeon. The Demon Lord can no longer interfere; only the deployed forces can protect the Summoner.

Assault the Goddess's Church

After defeating a certain number of Heroes, an opportunity for a counter-offensive arises. Capturing the nearest church will incorporate the land into the dungeon.

Law of Non-Interference

The Demon Lord cannot interfere with Heroes, and Heroes cannot perceive the Demon Lord. Only terrain and monsters can be manipulated; artificial structures cannot be built.

Law of Protection

The Summoner is protected from monster attacks, but if caught by a Hero, she can die from even the weakest blow. Her survival is the prerequisite for everything.

Law of Reproduction

Natural reproduction takes time but is sustainable; summoning is immediate but consumes mana. The circulation of the ecosystem determines the fate of the dungeon.

Law of Mana

Mana replenishes daily based on the number of lower-tier monsters and the health of the ecosystem. Richer lands can summon more powerful beings.