The Hero Became The Son of The Demon Queen

"Haah, haah…."

Damn bastards. To think they would collapse the entire castle just to kill me. And where did all those things come from? Magic circles, magic tools… just how much money did they pour into this?
Ha! Still, they wouldn't even dream I'm still alive.
...Well, honestly, can I even call this alive?
I covered the hole in my stomach with my hand.
But it's too big. I was somehow stopping my intestines from spilling out, but due to the forced warp magic, my mana was almost depleted, and my body was in no condition to think straight.
"Cough!"
I coughed up blood onto my other hand.
Not the blood of those I killed.
My own red blood.
To think the day would come when I'd be injured this badly. I guess I'm human after all.
But there's still hope.
"…Hero?"
Luscious wavy black hair came into view.
"Heh, how many days has it been. Demon Queen?"
The Demon Queen, whom I had knocked unconscious and secretly hidden away during the final battle.
"What in the world…."
I used the last of my strength to teleport here, to this hideout, of all places. If it was a plan to collapse that castle, then everyone except me must have participated.
…No, that woman probably didn't even know about it, let alone participate. But for some reason, it wasn't her that came to mind, but the Demon Queen.
"It's just as you see. Cough, …the pathetic end of a hero betrayed."
I coughed up blood once more, and my strength left me. Maybe it was because I had reached my goal of meeting the Demon Queen. They say humans unconsciously release their strength when they're close to achieving their goal.
But that's not important right now.
"How can you, who defeated me, be so injured?"

"I'd like to explain everything… Heh, cough! …But I don't think I have enough time."
The Demon Queen, looking flustered, gently held his body and laid him down with her lap as a pillow.
"Huh, to think I'd be getting a lap pillow from the Demon Queen…. It's softer than I expected."
"…Before being a Demon Queen, I am also a woman."
"Right, you're a woman too. And a very beautiful one at that…."
My vision started to blur. Maybe that's why the Demon Queen's eyes seemed to be filled with tears.
Though there's no way she'd cry for someone who fought her to the death and then kidnapped her and hid her away like this.
"Do you know why I hid you?"
"…I think I understand now."
"Right, if I were betrayed… I needed someone to take revenge for me."
"If you anticipated betrayal, why didn't you run away or make the first move?"
"Even so… they were the ones I spent years with. At the very, very end… I wanted to believe in them."
The faces of those damn bastards came to mind.
The Archmage. The Warrior. The Dwarf Paladin. The Saintess. The Elf Archer. The Beastman Martial Artist. And the Spirit Mage. …Ah, that guy died in the middle of the war. Maybe he lost too much blood, because his head seemed to be messed up too.
…Damn it all.
"But I was stupid."
My voice started to crack.
Maybe because my mana was depleted, I could feel my intestines slowly spilling out.
"Demon Queen. …I'm sorry to ask you this… but please take revenge on them for me. You can do it, right? …Honestly, the Demon Lord's army was only stopped because of me, right?"
"That's right. It was all because of you. Honestly, the others were nothing special. Only… you were a monster."
Monster.
Yeah, I was a monster.
The title of genius wasn't enough. Despite being human, I possessed overwhelming talent and innate mana, becoming the strongest in the kingdom before even reaching twenty.
Just as the Demon Lord's army began to stir, I stood in their way and somehow became the Hero.
I became the Hero and received the adoration of the people, but…
I was anxious.
Because I knew my own talent and power.
Because I knew how much people feared me even as they adored me.
So I created several hideouts, prepared some measures, and as a last resort, knocked out the Demon Queen and hid her here.
There was no way the Demon Queen, let alone the ragtag party members who couldn't even handle a single one of the Four Heavenly Kings alone, would ever find out.
"Just before I die… can I ask you one thing?"
I was speaking, but I couldn't tell if my voice was coming out properly.
"…What is it."
Fortunately, she seemed to hear me. But maybe my ears were already shot, because the Demon Queen's voice sounded incredibly sad.
"What's your name?"
"My name… my name, you ask."
"Quickly… tell me…. before I lose consciousness…."
"…I'm sorry, Hero."
"...."
"I cannot fulfill your request."
I see. Well, that's understandable.
There's no way she'd tell her name to the Hero who fought her to the death and then kidnapped her.
As I thought that, my vision brightened.
It was as if an unknown light was emanating from the Demon Queen.
'What's…?'
As I questioned it in my mind, as if she had heard me, the Demon Queen's voice reached my ears.
"There are three forbidden magics for demons. Among them is reincarnation magic. Originally, it's a magic to escape death by turning oneself into a baby using the life force of another demon as a sacrifice… but I will use it on you. Using my power as a sacrifice. The chances of failure are high, and I don't know what side effects there might be, but even so…."
'Demon… forbidden… magic… sacrifice… side effects? I don't understand what you're saying.'
It seemed like the Demon Queen was saying something, but my ears were muffled, and I couldn't hear her properly.
Whatever.
I'm going to die anyway.
And so, I quietly ended my life.