Brain Unglaus was born in a remote mountain village in the southern Kingdom. As the second son in his family, he would likely have spent his entire life working the fields, becoming nothing more than an unremarkable farmer.
At the time, Brain thought that would be fine. He would marry a plain village girl, have children, and pass his days in quiet stability, living out his life without incident.
But fate had other plans.
A greedy noble set his sights on the village. Small though it was, he squeezed every last coin from the villagers.
The excuse was laughable. The Empire and the Kingdom were at war, he said. For better protection, for a brighter future, taxes had to be raised.
Brain was furious.
If they could not even survive the present, what use was talk of the future?
One moonless, wind-swept night, a bold idea took root in his mind.
He picked up a short sword and hid along the path the noble would take on his way home.
When the man entered a small grove, Brain struck. With a single swing, he severed his head.
Hot blood sprayed across his face. Brain gasped for breath, hardly believing it. He was just a farmer, yet he had killed so easily.
"Maybe I'm a genius."
Staring at the sword in his hand, Brain felt as if he had finally found his calling.
And so, the man named Brain set out on a journey. Taking the noble's money, he pursued the peak of martial arts.
Over the following decades, he traveled far and wide, studying under various masters and honing his skills. He grew stronger without ever tasting defeat. So long as he held a blade, he felt unstoppable.
The feeling thrilled him. He began to believe he was chosen by fate. His ambition swelled.
He wanted fame. He wanted the entire Kingdom to speak the name Brain Unglaus with awe.
To that end, he entered the Kingdom's royal tournament, determined to claim the championship and make his name known.
Reality struck him hard.
He lost.
The undefeated Brain fell in the finals.
A man named Gazef narrowly defeated him. As Brain lay on the dueling grounds, disbelief was written all over his face.
It was his first defeat.
People said his strength was no less than Gazef's, that their abilities were nearly equal, that his loss was still honorable.
Brain did not see it that way.
A loss was a loss. There were no excuses.
He could not accept it, yet he did not run from it either. The pride and arrogance he once carried were shattered by that defeat and faded away.
Brain did not fall into despair. Instead, a thought took root in his mind.
"Why did I lose? Was it luck?"
"No. It wasn't luck. It was weakness. I wasn't strong enough."
"If I become stronger, that's all there is to it."
Gazef had only worked harder than he did. In terms of talent, Brain did not believe himself inferior.
He began tempering his body, refining his techniques, and obsessively studying Martial Arts. As long as it could make him stronger, he embraced it without hesitation.
In the end, he succeeded.
Relying on the ability known as [Talent], Brain created a Martial Art that belonged to him alone.
To fully master it and continue growing stronger, he joined a mercenary group as their main combatant.
Though this so-called mercenary group was little more than a band of brigands, robbing, killing, abducting women and committing every sort of crime, Brain did not care.
He was a self-centered man. As long as it made him stronger, nothing else mattered.
At this time, he truly was like that. His change would only come later, after meeting Shalltear, and then again during his lowest point, when he encountered the Warrior Captain.
...
Inside a pitch-black cave, Brain carefully wiped his sword with an oil-sheened cloth.
"Just wait, Gazef. I'll come to you soon and wipe away that humiliation."
Seeing his reflection in the polished blade, Brain smiled confidently. After today, he intended to leave this place and seek out Gazef for another duel.
He did not have absolute confidence. While he had grown stronger, Gazef surely had as well.
Even so, he would go.
Only through battle could he continue to advance.
Just as he was imagining their clash, a strange noise came from outside, snapping him back to reality.
He turned to see a mercenary stumble inside, his face pale with panic. Only after spotting Brain did he seem to regain a bit of composure.
"Brain-san, we're under attack!"
The mercenary rushed to him, gasping for breath, sweat dripping down his face.
"Calm down. With me here, it's nothing."
"How many are there?"
Brain remained composed, his expression steady.
This group had committed countless crimes. It was only natural someone would come knocking sooner or later. The reason Brain had stayed was precisely to fight strong opponents and temper his Martial Arts.
"N… not people. It's a monster!"
"A monster?"
Brain was slightly surprised, but quickly dismissed it.
Human or monster, it made no difference to him.
After all, he was Brain, the genius swordsman.
If a monster had come to his doorstep, even better. He was already tired of killing people. Slaying a monster might bring new insight.
"Leave it to me. Show me the way."
Drawing his sword, Brain strode out confidently. After hesitating for a few seconds, the mercenary followed.
That pitch-black monster probably won't stand a chance against Brain-san, the mercenary told himself.
And so they walked out together.
With a confident smile, Brain headed toward the unknown enemy.
He did not know that this confidence would soon be shattered.
On this day, the man named Brain Unglaus would lose not only his pride as a swordsman, but even his qualification to remain human.
Oh, and a few hundred hearts as well.
A brand-new, unimaginable vampiric existence was already reaching out to this so-called genius.