A Middle-Aged Man, Naked After Being Hit by a Truck, Gets a Cheat Skill from a Goddess to Be Permanently Invisible, Reincarnates in Another World, and Saves It!

[Note] Following this adventurer party is a middle-aged man, completely naked, who became permanently invisible due to a cheat skill granted by a goddess upon his reincarnation into this other world. Please be aware of this if you are uncomfortable with it.

One

Deep within the Demon King's castle, located on a remote island surrounded by treacherous rocky mountains, two adventurers were making their final preparations. It was a save point, so to speak, right before the final boss. One was Iseka, a young mage wearing ancient robes enhanced with beautiful runes, and the other was Tensei, a dashing young swordsman who wore magical light armor and favored a blessed, well-honed holy sword of mithril silver.

"It's finally time for the battle with the Demon King."

"We might finally be able to avenge your father. No, we definitely will."

"Yeah, that's why we came all this way!"

"Yes, that's right."

Tensei's journey began when he met Iseka while she was searching for a lost item in town. Upon learning that Iseka's father had challenged the Demon King and been defeated, he agreed to help her take revenge, and they had fought their way through the Demon King's Four Heavenly Kings to reach this point. The two, who started as novices, had now become heroes worthy of legend.

"It'll be okay. Tensei is here, and my father has been watching over me the whole time."

Iseka replied with a smile.

"Whenever I felt sentimental remembering my kind father in the bath, I felt like I was receiving his gentle gaze from somewhere. When I couldn't sleep at night, I always felt a presence as if my father were in my bedroom. I'm sure he's still watching over me from heaven even now."

"Ah, your father... he was a magnificent hero... he must surely be watching over you."

A sentimental atmosphere flowed between the two. They lingered for a moment on the memories of their journey so far. However, they could not dwell on their thoughts forever. They had to achieve their goal of defeating the Demon King.

"Let's go, Iseka. Let's defeat the Demon King and bring this journey to a close."

"Yeah! You're right! Oh, wait. Let me just apply some lip balm one last time. My lips get surprisingly dry when I chant spells."

Iseka rummaged through her bag.

"Huh? Oh dear? I don't have my lip balm. Did I drop it somewhere?"

"Good grief. You've been losing things ever since the day we met."

The two looked at each other and let out a light laugh.

Two

Blessed by sacred magic, Tensei had already transcended the bounds of a hero, slicing into the Demon King's flank with a blade that possessed speed and power temporarily reaching the divine realm.

"Gwah!"

"Not yet! This is just the beginning, Demon King!"

He kicked off the floor in an instant and aimed his sword at the Demon King once more. (Double action)

"Tensei, I'm casting support magic!"

Drawing a goddess rune with the tip of her staff, Iseka began to generate brilliant magical power directed at Tensei's sword.

"Right!"

"Oh Goddess, please grant power to my friend's blade."

The torrent of magical power dwelled within Tensei's sword, and the holy blade increased its radiance even further. At the same time, Tensei, who had already leaped into the air, swung his sword toward the Demon King, slashing with all his might from the shoulder. Jet-black blood and dark, murky magical power leaked out, and the Demon King staggered slightly.

"Ugh, I was careless..."

"Iseka and I are invincible. Give up and return to the darkness!"

"Heh heh heh, then I shall bring out my trump card as well... It seems you two are quite close... It would be boorish of me not to send you a parting gift."

"Tensei, watch out!"

The Demon King held his palm up to the empty air, instantly manifesting a complex triple magic circle drawn in crimson-black light. Ominous spells were inscribed on the magic circle using 'Ancient Era Runes' that should have been lost.

"Behold the Lost Magic 'Da-Rekashinu'!!!" (Action taken when HP is 10% or less)

"W-what? 'Da-Rekashinu'?"

"N-no way... The Lost Magic 'Da-Rekashinu', which was sealed at the bottom of hell by the gods due to its extreme cruelty... The Demon King... How..."

Da-Rekashinu - Type: Lost Magic - MP Cost: All - Inflicts 'Irreversible Death (Lost)' on one random character from the opposing faction. This magic always hits, and its effect cannot be nullified by any means.

The Demon King laughed triumphantly. The color drained rapidly from Iseka's face.

"Hahahahaha!!! Now, whether it be the hero or the girl, I do not know which it will be, but prepare to receive a death from which you shall never meet again!"

“N-no, this can’t be... that one of us would die here... no... Iseka, run! I’ll hold them off!”

“No... it’s too late... and I don’t want to let Tensei die! At least let them target me!”

“Die!!! ‘Da-rekashinu’!!!”

Dark light converged from the magic circle, and countless beams were fired in random directions toward Iseka and Tensei, converging into energy that destroyed everything, followed by a massive explosion.

“Wihi? Gyoaaaaaaa!!!!!!”

Someone’s scream.

Then, the mist from the blast cleared.

There stood Iseka and Tensei, still alive, with only a massive, scorched hole left in the floor behind them.

“I-impossible! Da-rekashinu was a dud... this shouldn’t have happened.”

“Now, Tensei!”

“Yeah, I’ll finish this! Uwooooooo!”

Holding his holy sword in a horizontal stance, Tensei finally cuts the Demon King in two.

“G-Gwaaaaaaaaaaaaa............”

The Demon King’s death throes echoed, and it was all over.

“We did it... we did it, Father... thank you, Tensei...”

Iseka finally showed a heartfelt smile, just like the one she had back then, when she was with her father.

Three

Iseka and Tensei kept running up the shaking, collapsing stairs.

“Iseka! The Demon King’s magic power is fading, and the collapse is accelerating. Hurry, we’re almost at the surface!”

“Yes! It looks like we’re safe now, but don’t let your guard down, Tensei! By the way, Tensei. You can answer while we run, but what are you going to do from now on?”

I haven't thought about it! For now, let's get to the surface and talk it over together!

Before long, the light of the door leading to the surface appeared before their eyes.

==============================================

It was all over.

The Demon King's soul was cast back down into the Demon Realm.

The castle began to shake violently.

Iseka and Tensei lay down in a nearby meadow, watching the Demon King's castle crumble.

Light slowly gathered from somewhere onto the Demon King's throne, which continued to collapse. The light gathered near the hole left by that Da-Rekashinu, and eventually took the form of a beautiful goddess.

At the same time, at the bottom of the hole, the corpse of the naked middle-aged man, now in a miserable state with his limbs and head scattered, lost its invisibility and revealed its form.

On the crumbling Demon King's throne, the goddess spoke quietly.

Long time no see. I am the goddess who picked up your soul after you crashed the Shibuya Halloween festivities dressed as a naked specter and were hit by a truck, gave you one cheat ability, and reincarnated you into this world.

As the goddess spoke, a soul quietly floated up from the corpse.

Heh!

I promised you. I couldn't reincarnate you as a handsome hero or a villainess, but I promised that if you chose one ability and did something for the world, I would reincarnate you as whatever you truly desired.

Heh heh heh!

The soul made a strange sound.

And you chose the power of invisibility. You gained an ability that makes you impossible to confirm by sight or smell, and impossible to detect via magic unless using special methods like lost magic. However, I imposed a restriction that you cannot touch living organisms, as it could be used for crime.

Heh heh heh! Heh heh!!!

And you succeeded brilliantly for the sake of the world. You were judged as an ally of Iseka and Tensei by the lost magic that always kills someone from the opposing faction. You protected the two young people from the magic of random absolute death, and scattered your own body in the process.

Heh! Heh heh heh!!!

"Yes, you have saved the world, just as promised. It may have been a coincidence, but I will acknowledge that. Congratulations."

"Hee-hee-hee! Hee-hee-hee!!!"

Out of joy and a sense of accomplishment, not only his soul but also the erect penis of the naked middle-aged man, which had been torn off and sent flying, began to float in mid-air.

However, at this moment, the goddess's face suddenly turned into that of a demon.

"However!!!"

The goddess let out a terrifying voice.

"I have also been watching closely as you constantly peeked into baths and toilets in Iseka, and stole underwear, swimsuits, magical bikinis, and used sanitary products!!!"

"Hee!?"

As if his soul felt terror, it sparked and glowed red. The flying member fell to the ground, twitching and shrinking as it convulsed.

"Guilty! Guilty! Guilty & Guilty!!! Disgusting! Personally, I find you physiologically repulsive! I am voiding our agreement and casting you into the Avici Hell (a sentence of over one trillion years)!!! You have no complaints, do you?"

"Hee!!! Heeeeee!!!"

A bottomless, pitch-black hole opened in the floor, and the soul was sucked in while screaming. Once that was done, the goddess quietly returned to her original expression, dissolved into light, and ascended to the heavens. When that was over, the ceiling of the Demon King's castle collapsed, and it sank deep into the bowels of the earth.