Prologue

It happened suddenly on an otherwise-normal spring day. Every dungeon core within Haku’s faction launched challenges to Dungeon Battles. Their target? All the same dungeon: Core 10’s.

“All units, advance,” Haku signaled, and so all the dungeons invaded Core 10’s dungeon at once. Several Cores were assigned to branch dungeons instead, but attacking those would still put a burden on Core 10, which stood to benefit Haku. It would also allow her to prevent him from escaping through Dummy Cores, ensuring she could finish him off for good. Under normal circumstances, she would leave it at weakening him, so one of the Heroes she was raising could land the final blow and grow stronger, but as she was dealing with a First Lot Core, she intended to destroy him herself.

Core 10’s Main Dungeon, which she was invading with the bulk of her forces, was a traditional underground labyrinth. The entrance was disguised as a cave in a small hill of dirt, and advancing a bit farther inside would lead to the cave giving way to smooth stone walls and a cobblestone floor. The monsters that appeared were of various species, but the majority were undead, to reflect Core 10 being an undead-type Core.

“Good grief, what a troublesome opponent,” Haku said, sighing as she looked at her map. To be undead was to be sturdy, in general. And any monsters you sent would be turned against you upon dying. Core 10 was not a First Lot and Top Ranker for nothing—his dungeon was deadly.

Haku, for the purposes of better commanding her entire army, was not in her Master Room; she was camped in front of the entrance to Core 10’s dungeon and was giving orders to each of the Cores under her command. Under normal circumstances, a Dungeon Battle would entail connecting dungeons via portals, but due to the number of invaders, Core 10 was simply being swarmed; the area above had already been conquered and was safe.

Haku checked the front lines via her map while sitting on a one-person sofa. There was a platoon of Shine Minotaurs swinging light-elemental axes against a horde of mummies in white dresses. The axes had been effective against the undead on the way, but the surprisingly dexterous mummies did not take much damage from them.

“Undead with a resistance to light damage... How annoying.”

“My lady, I am told those mummies are the corpses of former High Priestesses and High Priestess candidates. It truly stimulates the imagination to imagine each of their stories,” extolled a cross-dressing woman with a grin, wearing a white tuxedo with gold embroidery fit for a stage—Core 219. She was the Dungeon Core of the [Garden of Light], located near Tsia. She, for her part, was using zombies as fertilizer to produce and send forth plant-based monsters.

“Meep! I found a side path! Here, I’ll share my map!”

Lastly was Core 629, the rabbit-type Core named Mikan. He was the Dungeon Core of the dungeon near the imperial capital where Keima had served as producer: the [Rabbit Rest Spot]. Haku did not have... high hopes for his combat abilities, but he was contributing greatly through using a horde of squirrels to make map progress.

“To think Core 629 would surpass my expectations to this degree,” Haku mused.

“This, too, is thanks to Lady Rokuko’s Master, no? Keima Goren...”

“...No, I will consider this Core 629’s accomplishment,” Haku replied, despite being forced to acknowledge that the squirrels running underneath the undead’s feet to unlock more map progress greatly resembled Keima’s rat strategy. That was obvious, as Core 629 had learned it from Keima.

Not to mention, this strategy was especially effective against their current opponent. Those who died in Core 10’s dungeon would be turned against them as undead... and indeed, several of the squirrels were being crushed beneath the undead’s feet as they ran. They were weak; far too weak. They exploded like nothing when stepped on. But that in turn meant their corpses were so violently mangled that it was actually more difficult to raise them as undead. And even if they were raised, squirrels wouldn’t provide any combat power whatsoever... Their weakness was counterintuitively proving to be a strong weapon against Core 10’s undead dungeon.

“Do not tell me... Will Core 629 be achieving the highest merits for this battle?”

“Work hard so that does not happen, Core 219. The same goes for everyone else as well,” Haku replied, and the Cores of her faction nodded through their monitors. The majority of them were Cores that existed within imperial territory. Many could not resist her, as their land had been conquered by the empire, and their lives had been left in Haku’s hands.

“Gyahahahaha! As if undead this weak could ever beat me! I’ll be winning those highest merits! I am strength incarnaaaate! That orange rabbit just doesn’t get iiiit!”

Core 564—a demon-type Core unable to resist Mikan’s orders—swung his giant scythe at the front lines, cutting a High Priestess mummy in half. As a former member of the Demon King faction, Core 564 apparently found mobilizing himself more to his taste than sending troops. Though it did’nt help that he didn’t have enough DP to summon troops in the first place.

“Still, this magic scythe is powerful indeed. It’s as if it were made for me! I shall name it Ultra Death Scythe.”

“Core 564. That is merely one piece of my private collection, which I am lending you; do not name it without my permission,” Haku said through the monitor.

Core 564 jerked and hastily straightened his back. “L-Lady Haku! I did not realize you were watching, ahaha... ’Twas merely a joke... Spare me...”

“That said... I am considering rewarding you with that scythe depending on the scale of your success here. If that comes to pass, you may name it as you like.”

“T-Truly?! O-Ooh, I shall fight with all my heart and soul!” Core 564 exclaimed, then ran off swinging at another High Priestess mummy. Cleaning up those somewhat-troublesome High Priestess mummies was well worth a single magic scythe. It was one of the harder ones to use in her collection, and it had been rotting away in one of her storerooms.

“Are you certain, Lady Haku?” asked Chloe, her cross-dressing Succubus butler, once she ended the call with Core 564. That scythe was technically at the higher end of her collection, to the point one could build an estate in the rich district of the imperial capital with the proceeds.

“Quite certain, Chloe. It will be a fitting payment if he does indeed do work worth compensation,” Haku replied. If he did handle all of those High Priestess mummies, then she could also give a portion of Keima’s payment to the subordinate of one of her subordinates, killing two birds with one stone. That would be the most useful thing that scythe could do.

“Still, I feel unsettled,” Chloe said.

“Oh my. Did you have a fear of the undead all along?”

“That is not what I was referring to. Rather, this is progressing far too smoothly... We are dealing with Core 10, are we not?”

“Ah, that.”

Core 10 was, once again, a member of the First Lot—the first Cores to be created. On top of that, he was a Top Ranker, which meant he was in the Top Ten on the rankings list. That made him a veteran of veterans who had survived countless months and years of conflict. Why, then, was he using nothing more than the basic strategy of sending waves of monsters? Even considering the size of Haku’s assault, Chloe was likely right in that he was surely planning something.

“According to Keima’s report, he was weakened by the remnants of the God of Light, and this may still be having an impact.”

“Even if he was unwell, surely he could trust the fight to his subordinates?”

“He could, if he had subordinates he could trust as I trust you,” Haku said. The majority of Cores did not trust their dungeons to subordinates. One felt resistance to essentially entrusting their entire bodies to others to use as they pleased. It wasn’t quite on the level of, say, living together, but you needed to at least trust someone enough that you would rest your head on their lap and let them clean your ears. Core 10 had betrayed Father and sided with the God of Light, so in the end, could he trust his own subordinates...? It was not hard to imagine that the answer was no.

“Oh, next up are Giant Zombies. They have Troll Zombies with them... I wonder how much DP these cost?”

“They are rather fast, too. He must have enhanced them significantly, my lady,” Core 219 said. The monsters were no slouch, either. It did not seem like Core 10 was slacking, at the very least.

＊ ＊ ＊

It was many against one. Although Core 10 was a First Lot Top Ranker, Haku was similarly a First Lot Core, and one higher than him in the rankings. With her leading a veritable army of Cores in battle, Core 10 had no hope of winning. His forces were pushed back, any side paths were crushed, and his dungeon was conquered. Mana-sight was used to identify and destroy any possible escape routes.

And so, after half a month of constant battling, Haku’s army managed to completely fill Core 10’s dungeon. However, this had been accomplished far faster than expected and with far fewer casualties. Mikan’s squirrel platoons contributed to that significantly.

“...To think that rabbit would...