The sky was overcast as muffled thunder rumbled in the distance.
Sebastian stood with his back pressed against the door panel, looking around the unfamiliar room.
Suddenly, his legs gave out, and he collapsed to the floor.
“Did I actually transmigrate?”
Crack!
A bolt of lightning tore through the dark clouds, and a heavy rainstorm crashed down outside.
As the lightning flashed, Sebastian raised a hand to rub his temples, desperately trying to process the fragmented memories in his mind.
It was true—he had transmigrated.
Not only that, but his body had shrunk into that of a teenage boy.
His first name was still Sebastian, but his surname was different now: Sebastian Lucifer.
He had become a direct descendant of the Lucifer Clan, one of the original Four Great Satans of the Old Satan Faction.
He even had an estranged half-brother named Vali.
At first, terms like “Old Satan Faction” and “Four Great Satans” meant nothing to him.
But the moment he recalled memories of Vali, everything clicked into place.
This was the universe of High School DxD.
Sebastian had watched the anime years ago before dropping it due to work, but its unique world and art style had left a deep impression on him.
The more he recalled his new identity’s past, the colder his back felt:
His useless father was dead.
His grandfather was a complete lunatic.
He was the only person left breathing in this empty house.
Although he and Vali shared the same father, they had different mothers.
Vali was a half-devil, half-human hybrid, while Sebastian was a pure-blooded Devil.
Logically, Sebastian should have possessed greater talent, but reality was the exact opposite.
Vali was a monstrous genius—the current host of the Divine Dividing and the legendary White Dragon Emperor.
Sebastian, on the other hand, was a pure-blooded Devil with talent so terrible it was embarrassing.
He even had black hair, completely different from the rest of his family.
His mother had died giving birth to him.
As for his father, his grandfather—Rizevim Livan Lucifer—had murdered him just five days ago after Vali escaped.
Rizevim was the strongest Super Devil, a monster who killed whoever he wanted on a whim.
Now, this giant mansion housed only a few servants, Sebastian, and Rizevim.
Having seen the original story, Sebastian knew Rizevim was a total psychopath.
Bored of his own universe, the old man became obsessed with conquering other dimensions, completely ignoring that the EXE World was even more dangerous.
His actions in his own world were absurd: forcing his son to abuse his grandson, killing his son for being weak, and plotting to unleash the Great Beast 666 before dying.
Sebastian shivered.
Who knew when Rizevim might decide he was an eyesore and murder him too?
I should have taken the risk and run away when Vali escaped, Sebastian thought grimly.
Vali had only made it out because loyal servants risked their lives for him, but even that was better than staying in this house.
How am I supposed to survive now?
I wouldn’t even be surprised if I got killed tomorrow.
As he leaned against the door, lost in thought, a voice suddenly sounded from right behind him.
Terrifyingly close.
“Sebastian.
Open the door.”
Sebastian could never mistake that voice.
It was Rizevim.
He had no desire to see the old monster, but hiding was impossible.
Taking a deep breath, Sebastian gritted his teeth, stood up, organized his chaotic memories, and opened the door.
A man stood outside.
He wore the armor and robes of the Lucifer Clan.
He looked very similar to Vali, with a bit of stubble on his face, yet he maintained a young appearance.
He stepped inside without waiting for an invitation.
Rizevim was the son of the original Lucifer and Lilith, the Mother of Devils.
He was the strongest Super Devil and possessed the terrifying ability of Sacred Gear Nullification.
The moment he entered, his gaze locked onto Sebastian.
They were family by blood, yet Rizevim looked at him with eyes as cold as steel, scanning him from head to toe.
To Rizevim, Vali had at least been worth teasing.
But Sebastian?
Sebastian didn’t even meet the qualifications to be his toy.
Despite carrying the bloodline of Lucifer, Sebastian’s magic power was pitifully weak and his physical abilities were terrible.
Pure-blooded Devils couldn’t naturally possess Sacred Gears, and Sebastian was slow at learning magic and lacked any special talents.
He was a complete disappointment.
Normally, Rizevim wouldn’t even glance at him.
But circumstances had changed.
Vali had escaped, and he had killed his own useless son.
That left Sebastian—the worthless grandson—to step up and act as a figurehead.
Rizevim had his own grand designs.
For the next few decades, he needed to handle Sirzechs Lucifer, the leader pushed forward by the Anti-Satan Faction (Reformists).
With his son dead and Vali gone, the Old Satan Faction still needed a Lucifer to sit on the throne.
Sirzechs was far too soft-hearted and hadn’t wiped out the Old Satan Faction completely after the civil war.
Besides, pure-blooded Devils were scarce now.
Even if the Old Satan Faction was full of useless fools, the Anti-Satan Faction had to tolerate them to maintain a united front against the Angels and Fallen Angels.
Thinking about this, Rizevim decided that Sebastian’s uselessness was actually a good thing.
A fool standing among other fools wouldn’t draw unnecessary attention.
He was the perfect puppet to place inside the Underworld while Rizevim worked in the shadows.
Vali had been too talented for the job, and his son had been too cowardly.
Rizevim studied the boy in front of him.
Surprisingly, Sebastian stared right back into his eyes.
Rizevim intentionally stayed quiet to intimidate him, but the boy didn’t look away.
A useless fool, Rizevim thought to himself, but at least he has some nerve.
In truth, Sebastian wasn’t staring because he was brave.
The moment Rizevim walked into the room, a clear, mechanical sound had echoed inside his mind.
The mysterious voice spoke again, heard only by Sebastian:
[Maintain eye contact with Rizevim for one minute: Condition Met.]
[Check-in Successful!]
[Reward Obtained: Yamato.
Automatically bound—usable only by the host.]
[The reward has been stored in your System Inventory.]
“Are you really going back to the Lucifer estate just to take care of that boy, Sebastian?”
Rias Gremory stared at the silver-haired woman standing before her, who had put on her maid outfit once again.
Rias couldn’t understand her decision at all.
Grayfia Lucifuge had once defected from the Old Satan Faction during the civil war, yet now she was willingly returning to serve them.
Even though Rias was still young, she knew how much hatred and insult Grayfia would face by going back.
Yet Grayfia—a woman powerful enough to rival Serafall Leviathan for the title of the strongest female Devil—refused to change her mind.
“Rias, the Old Satan Faction is different now,” Grayfia said calmly.
“I will be targeted, but given my strength, those Devils won’t dare attack me openly.”
The Old Satan Faction had been crippled during the war.
Now that Rizevim had abandoned them, they couldn’t even find a single Satan-class Devil among their ranks.
Grayfia wasn’t worried about her own safety.
She was worried about Sebastian.
“His mother was my dear friend,” Grayfia continued softy.
“Before she passed away, she begged me to protect him.
Sebastian is weak.
His father is dead, his brother ran away, his grandfather is a monster…
and Rizevim has now vanished from the Underworld.
That child is completely alone and hated by everyone.”
Grayfia picked up her luggage.
The legendary Queen of Annihilation, now dressed in her maid uniform, reached out and gently patted Rias’s head with a rare, gentle smile.
“Don’t worry about me, Rias.
I am a member of the Lucifuge family.
For generations, we have served as the right hand of Lucifer.
Taking care of him is my duty.”
She stepped back as Rias pouted up at her.
Grayfia’s smile vanished, returning to her usual icy demeanor.
“Go back and tell your brother…
we are truly not meant to be.
He has his path, and I have mine.
Goodbye, Rias.”
Carrying a simple leather suitcase, Grayfia turned and walked toward the territory of the Lucifer Clan.
Rias watched her leave until her figure disappeared into the fog.
Then, she turned toward the shadows nearby.
“Brother…
Grayfia said you aren’t meant to be.”
Sirzechs Lucifer, the current Great Satan, slowly stepped out from the corner.
He looked in the direction Grayfia had gone and let out a long sigh.
He truly loved her, but Grayfia had never returned his feelings.
Although he had expected her rejection, it still hurt his heart.
Even so, Sirzechs wasn’t the type of man to force someone to stay.
He could only silently pray for her safety.
“Let’s go back, Rias,” Sirzechs said softly, turning away.
“The Yamato truly lives up to its reputation…”
Inside his room, Sebastian gripped the hilt of the legendary blade and slowly drew it from its scabbard.
He gave it a casual swing at the empty air before him.
Without using much force, the silver blade sliced open a pitch-black rift in space.
Only when he sheathed the sword did the spatial tear slowly stitch itself back together.
“I can cut through space itself so easily…”
Sebastian smiled softly.
At the very least, his offensive power was now absolute.
Yamato was far more than just a spatial blade.
Its true power was Separation—the ability to slice through anything the user willed, including abstract and conceptual boundaries.
It could open portals, cut space, and even separate a soul from its body.
Its power easily rivaled top-tier Sacred Gears.
“Now I finally have the power to protect myself.”
With a thought, Sebastian stored Yamato back into his System Inventory.
In a way, he now held two distinct powers: the Yamato and his System, which allowed him to store items and receive rewards.
The Check-In System was simple: whenever he encountered key figures from the High School DxD universe and fulfilled specific prompts, he would receive rare rewards.
With this system, gaining real power was only a matter of time.
Sebastian walked over to the window, looking out over the grand, ancient castle of the Lucifer Clan.
Although the sky of the Underworld was perpetually gray and gloomy, Sebastian felt as if the entire world had grown brighter ever since Rizevim left.
The crazy old man was gone.
He hadn’t just stepped out for a walk—he had completely abandoned the Underworld to begin forming the Khaos Brigade in secret.
He’s probably busy gathering terrorist factions right now, Sebastian thought.
But for me, his departure is the greatest blessing.
When Rizevim left, he took most of the powerful elder Devils of the Old Satan Faction with him.
The faction’s overall military strength had fallen drastically, but that was actually a good thing—it meant the remaining faction members were weak, easy to control, and terrified of drawing the Anti-Satan Faction’s wrath.
For the time being, Sebastian was finally safe.