A Regressor's Bucket List

He couldn't be called a member of the 'Suicide Squad', but Shuten was a guy who stayed with the Suicide Squad until the very end, fighting in the War against Demons.

Though he had a more Magical Beast-like appearance than anyone, he fought back-to-back with us, tearing through and devouring the Demon King's Army until the end.

It was an ambiguous position—too vague to call him a friend or a teammate, but not quite wrong to call him a comrade-in-arms.

Of course, that's not to say we interacted much.

His pattern was to stay holed up somewhere out of sight, only appearing when it was time to hunt Magical Beasts.

Because of this, most of the Suicide Squad members, who had only heard scattered rumors about him, knew of his existence only as the protagonist of a 'ghost story about a Magical Beast that hunts Magical Beasts'.

Therefore.

I, who would go out of my way to find his hiding spot and talk to him outside of battle, was pretty much the only link between the Suicide Squad and him.

…The day I first heard his inner story was one such day.

A battle had just ended, and I sat down next to him as he was sharpening his sword on a log, far from the barracks.

Grind— Griiind—

"How many?"

I sat next to him as he sharpened his Dark Sword using a Mana Stone as a whetstone and asked my usual question. An answer came back immediately.

"...Eight hundred thirty-one."

"Oh. I got two more than you."

His head slowly turned.

"...Eight of them were Named-grade. I'll be generous and count each as two. That means I got six more than you."

"Hey. If we're counting like that, I got five Named ones too. And I killed the Baron."

"...Don't be ridiculous, kid. I was the one who severed three of its limbs. How does that make it your kill?"

"Because. I'm the one who cut off its head."

Ssk—

"...And I have the proof right here."

As I took out the Mana Stone harvested from the Baron's body and held it out, he stared at it for a moment before taking it and muttering quietly.

"...Half of it is rightfully yours, so I'll pay you back later."

"After you're dead?"

"...If I die, you can have my Mana Stones. That would be a more accurate calculation."

Pfft—

"Of course you would."

A moment of silence passed before I asked him.

"What's your story?"

"...What do you mean?"

"There has to be a reason. For someone who was once part of the Demon King's Army to be going around thrashing Magical Beasts like this."

From his first appearance, there were many rumors about 'Shuten'.

An unidentified Magical Beast who would subtly appear whenever the Suicide Squad had a battle, hunt Magical Beasts, and then disappear before the battle was completely over.

After it was revealed that he was Shuten, a Baron of the Demon King's Army, opinions within the Suicide Squad were divided, with some saying he should be hunted down and tortured, and others that the bud should be nipped.

It was settled for the time being when the Bamboo Hat Mister, who was the strategist for the Suicide Squad at the time, made the decision to 'wait and see'.

This ambiguous coexistence, like that of a planet and its satellite, continued for a while.

And it was on this day that I, the only one who had managed to get him to talk, finally gave in to the prodding of some Suicide Squad members and asked him.

To my question, 'What's your reason for killing Magical Beasts?', his answer was surprisingly simple.

"Vengeance."

Vengeance.

"...It's because of my desire for vengeance against the one who abandoned me."

One of the most potent emotions an intelligent being can possess, another name for 'a hatred that robs you of sleep'.

…To be honest, it wasn't like I had no idea when I asked.

There were only a few possible reasons one could think of for a guy who acted as the Demon King's hound to turn his sword against the Demon King.

And the Bamboo Hat Mister, who seemed to know a thing or two, had hinted as much.

"...Well, I heard the gist of it. That you were kicked out of the Demon King's Army."

However, what I was curious about were the details.

It was hard to imagine a reason for a guy who was recognized within the Demon King's Allied Forces and even received a title to be kicked out.

"..."

After a brief pause, he opened his mouth and asked.

"How much do you know about me?"

Sensing he was about to tell me, I quickly wracked my brain and answered.

"Well, you're one of 'Japan's Three Great Evil Demons' who raised hell on the archipelago..."

To briefly touch on this.

…The existence of the 'Hero' alone was proof, but the barrier between the Upper Plane and the Lower-Dimensional Plane was not perfect.

Because of this, traces of the Upper Plane remained in the Lower-Dimensional Plane.

And these traces gathered to form the 'myths', 'folktales', and 'legends' passed down in various regions around the world.

Of course, due to the difficulty of proof, apocryphal tales arose, and not a few parts were passed down with the context cut out or distorted.

The myths passed down from antiquity, now treated as 'scientific fiction' in modern times, were often actual history from the Upper Plane, or records of special beings who ascended to the Upper Plane.

And 'Shuten', befitting his high status as a Baron in the Demon King's Army, had also left a clear legend and name in the Lower-Dimensional Plane.

'Japan's Three Great Evil Demons'

Among the countless yōkai and strange beings that plagued the archipelago, the three great monsters said to have been the most long-lasting and notorious.

'Sutoku Tengu, the White-Faced Golden-Haired Nine-Tailed Fox, and... Shuten-dōji.'

One of those evil demons was this very guy.

The villain from the legend, known as the chieftain of the Oni who lived on Mount Ōe, committing evil acts like cannibalism and kidnapping, before being tricked by a Japanese warrior and beheaded.

That was about all I knew of Shuten's story at the time.

"...Chieftain of the Oni?"

"...You know less than I thought."

"Wouldn't it be weirder if I knew the details? I even had to study to know this much. For today."

"..."

Thud—

Ssk—

Shuten, who had been staring at the ground in silence, soon put down the sword he was sharpening and held up a single finger.

"...What, you want another Mana Stone?"

I asked jokingly at his sudden action, but he shook his head and answered.

"...The Oni race has a certain mystical ability."

"..."

"Cannibalism. To put it simply, it's an ability that makes one stronger each time they devour another Oni."

And then, with a bitter expression, he began his story.

"...Of course, not every individual possesses this ability. Only special individuals among the Oni, called 'Dōji', are born with it. I, too, was born with this ability from birth."

"...You're scarier than I thought."

"Don't worry. It's an ability that doesn't apply to humans anyway."

"..."

"...They don't taste good anyway."

"..."

"Well, anyway. Originally, there were a few more of these special individuals called 'Dōji'. Though I was the strongest among them, just the same."

His following explanation was a part I was already familiar with.

Before coming here, a mythology geek who was a member of the Suicide Squad had talked my ear off about the legend of 'Japan's Three Great Evil Demons, Shuten-dōji'.

The story he'd recited contained the exact same details.

"...I thought all Oni were beings I had to devour, but I found that I got along surprisingly well with a fellow named 'Ibaraki-dōji'."

"..."

"That's when I thought. If I'm the strongest anyway, is there really a need to devour more... or so I thought."

"..."

"Gathering the Dōji and Oni and settling down on Mount Ōe was ultimately because of that thought."

"...That was a foolish thing to do."

Pfft—

"Yes. It was a foolish thing to do. I gathered a bunch of bastards who were just waiting for a chance to backstab me all in one place."

From here on, the story differed from the legend I'd heard from the geek.

"...They brought a human, saying he was verified, so I trusted them. Because the ones I trusted most vied to vouch for him."

The great monster, Shuten-dōji, who had driven the archipelago into terror.

In the legend, it was recorded that a certain Japanese warrior defeated him, but the reality was a little different.

The reason that warrior was able to safely enter Shuten's castle and feed him the potent poison called 'Shinbenkidokushu' was all thanks to Shuten's four Dōji subordinates.

Because they had joined the warrior's scheme.

"So. You got backstabbed, barely escaped with your life, hid, and then got your revenge... is it some kind of cliché development like that?"

"...No."

"...?"

"I tore them all apart and devoured them right there on the spot."

"...Huh."

"Didn't I tell you? I was the strongest."

This part was different, too.

In the legend, it's said that Shuten was beheaded by the warrior.

"On the spot, I devoured all four of those Dōji bastards, handed the warrior Ibaraki's head, and ordered him. Told him to say it was my head."

"..."

"Right after that, I crossed over from the archipelago to the central continent."

He had said that, on the contrary, he had butchered and devoured the four Dōji on the spot.

Unlike that bastard Jerry, who lied as easily as he breathed, Shuten inherently hated lying, so there was no chance it was a lie.

"Back then, I was at a point where I couldn't stand it if I wasn't fighting something."

"..."

"I traveled around meeting the many strong individuals that didn't exist on the archipelago. Looking for an opponent stronger than me."

The development was roughly predictable, but I asked anyway.

"...And then you met the Demon King and went to serve under him?"

"...That's right."

"..."

"That was my second foolish act."

Because a question arose in my mind.

"That's strange."

"..."

"...Normally, right after getting backstabbed so spectacularly, you wouldn't be able to trust anyone, let alone feel skeptical."

I'd heard it as a joke before.

The story that 'anyone who has spoken to the Demon King even once cannot help but follow him.'

But even so, Shuten's situation was too extreme.

After being backstabbed and having everything he'd built his entire life—his 'subordinates' and his 'pack'—denied, trusting someone was not as easy as one might think.

To my question, Shuten replied with an even more bitter smile.

"...That's why I said it was my second foolish act."

"..."

He paused for a moment, then looked down at his right arm as if reminiscing and continued.

"These protrusions weren't the only thing I gained from devouring the four Dōji."

"...!"

"I gained the ability to see through lies."

I didn't know it at the time, but he said that was also why he only spoke to me among the many members of the Suicide Squad.

Because, at least when he encountered me during battle, I wasn't someone who spouted lies.

"From my perspective at the time, the Demon King was quite special."

"..."

"He was the first opponent to ever defeat me."

"..."

"To me, who had never once stepped down from the position of the strong, he made me understand for the first time what it felt like to be the weak. And..."

Ssk—

His gaze now turned to the 'Dark Sword' he had received from the Demon King.

"...After leaving the archipelago, the Demon King was the first one to tell me he needed me, without a hint of falsehood."

"..."

"For me back then, that was enough."

Pfft—

"Though in the end, I ended up like this, an abandoned hound."

"...You really are an illiterate simpleton."

The end result of Shuten's decision to follow the Demon King was simple and miserable.

In the early days, when the Demon King was busy expanding the power of the Demon King's Allied Forces, he needed Shuten.

But once the expansion of power was more or less complete and it was time to solidify that foundation, he was no longer needed.

Countless Titled Demons who had knelt before Shuten's outstanding combat skills joined the Demon King's Allied Forces, but the grudges remaining in their hearts became an obstacle to the Demon King's work of consolidation.

Shuten's military might was a waste, of course, but it's always far easier to discard a single piece than to move the hearts of the many.

And so, Shuten.

Was abandoned by the Demon King.