The boy was the son of an unexpectedly famous devil…
"...Well, whatever. You're you. So, kid, which name do you want to be called by?"
"W-well, I like being called Renya, the name my mom gave me... I like it. I also like Japan, my mom's homeland."
The boy—Renya—who seemed to have Japanese blood from his mother, smiled a childlike smile as he said this.
"Hooh, I don't mind that country either. But, kid, you really love your mom, huh?"
"Th-that's not..."
"Yeah, don't be embarrassed. I'm not making fun of you. Valuing your parents and family is a good thing."
The young man laughed and roughly ruffled Renya's hair, who looked bashful.
"Alright then... In that case, Renya, to make sure things go smoothly from now on, you need to properly convince your family."
"Y-yes! I'll do my best! ...Um, Master? Master, what's your name?"
Asked by Renya, who was fixing his now messy hair, the man scratched the back of his head as if he'd forgotten.
"Huh? Ah, right, I didn't introduce myself. My bad, my bad. I'm Cú Chulainn. Well, I'm more of a reincarnation than the original guy himself, but if I drop this name when convincing your family, it should make things a bit easier, right?"
"Eh? ...Eeeeeeeeeeeeehhhhhhhh────!?"
After a beat, Renya let out a cry of astonishment at the name the man had given.
The young man—Cú Chulainn—winced at Renya's volume and leaned back.
"The hell's so loud! What? You know it?"
"B-because! Cú Chulainn is the great Irish Hero, the one called the 'Hound of Culann'!?"
Renya sometimes read heroic epics like picture books. Among them, the name Cú Chulainn was particularly memorable, partly because it was the first heroic tale he'd ever read.
──Cú Chulainn
That was the name of the great hero appearing in Irish mythology, the 'Ulster Cycle.' The son of the sun god Lugh and Deichtine, sister of Conchobar, king of Ulster.
The origin of his name came from when, as a child, he accidentally killed the guard dog of the wealthy merchant Culann. He vowed to raise one of the dog's pups to be a faithful guard dog himself and to protect Culann's household until then.
After reaching adulthood, he joined the famous "Red Branch Knights," studied under the Queen of the Shadow Realm, Scáthach, mastering numerous forms of magic, martial arts, and various other techniques she possessed, and was bestowed the legendary crimson spear Gáe Bolg. He was an exceptionally rare warrior.
He single-handedly repelled the great army led by Queen Medb of Connacht, who had invaded his homeland, Ulster. He slew even his own close friend Ferdiad, who was sent against him by Medb.
He captured Medb but released her because she was a woman. Because of this incident, enraged and bent on revenge, Medb ensnared him with various geasa (taboos/vows).
Even so, to protect his country, he accepted these geasa, knowing they would lead to his ruin. Through Medb's schemes, he was forced to break his geasa one by one, and finally, he was struck by the Gáe Bolg in his abdomen.
Even then, he was a great man who tied himself to a standing stone and continued fighting until his very last breath without falling.
His final stand later became known as "The Combat at the Ford of Ferdiad," and became a rune symbolizing the unyielding spirit of the Red Branch Knights.
He was truly a man worthy of the title Great Hero.
Receiving Renya's gaze full of respect, Cú Chulainn scratched his cheek with a finger.
"Yeah, that Cú Chulainn. Well, I've got the memories and experiences of the original, but strictly speaking, I'm not him. As I said, I'm his reincarnation. This me here hasn't accomplished anything special. I'm just a traveler, going where the wind blows, and my whims take me."
"N-no, but it's amazing! To be that great hero!"
Cú Chulainn wasn't being modest; he genuinely thought of it as ordinary. Renya, on the other hand, felt the sheer magnitude of the man's character and seemed excited.
Cú Chulainn grinned a manly smile at Renya's boyish attitude.
"Hahaha. Well, I don't mind it. Anyway, more importantly, you need to convince your family, of course, but for now, go stay by your mom's side. Looks like she protected you right up until the very moment your power awakened, huh? She's just a human, that's impressive. A woman like that is hard to find. Take good care of her."
"Y-yes! Then, Master, please wait here! Don't go anywhere without telling me, okay!?"
Renya started to run off, but stopped suddenly and turned back. Cú Chulainn waved his hand flippantly, telling him to go on.
"Yeah, don't worry. I'm not going anywhere. At least not until I've made you capable, or until the negotiations fall through. You're just a kid and a hybrid, but you're a devil, so do your best."
"Y-yes! I'm going, Master!"
"I said I'm not your master yet... damn, he's already gone. Kids are so energetic."
Seeing Renya run off without hearing him out to the end, Cú Chulainn smiled wryly. For now, he figured he'd wait for the result, sitting down and watching the clouds drift by.
That boy was in for a tough road ahead. The upper echelons of the devils were eager to get rid of him, a hybrid devil with no power, and being chosen by that spear only added to it. No matter what, a peaceful life was probably out of the question.
'If he gains power, gets recognized, and establishes his position as a High-Class Devil, it might be a bit different. Even then, he'll face strong opposition, but it should be better than now. The problem is what comes after that...'
Realizing he was already thinking about the boy's future despite not even being his official master yet, Cú Chulainn smiled wryly at how much he'd taken a liking to Renya.
"Well, things will work out as they will."
The means to survive aren't just about combat. If he also teaches him survival skills, covert arts, and social maneuvering, the rest would be up to Renya.
"No matter what you learn, you die when it's your time. But, well... I'd like to make it so he can choose what he wants to do."
Thinking that since he was going to teach him anyway, he wanted him to live a long life, Cú Chulainn stood up.
He saw Renya running towards him, waving, and the father being led by his hand, Mephisto Pheles, who wore a wry smile. Cú Chulainn shrugged.
"Looks like I'm about to get busy."
'Well, now, first things first,' he thought, considering what to teach him first as Cú Chulainn raised a hand in a casual "Hey" and walked towards them with his light-footed step.