Disclaimer: Arifureta Shokugyou de Sekai Saikyou belongs to Shirakome Ryo, and Itai no wa Iya nano de Bougyoryoku ni Kyokufuri Shitai to Omoimasu belongs to Yuumikan. I don't own those two.

Spoiler: This story takes place after the eighth event of New World Online in BOFURI WN. Takes your own risks.

Warning: Some spoiler from both LN and WN.

In the world known as Tortus, there's one being who lives on the top of the Divine Mountain. That being doesn't have a physical body, but he observed all of the living beings in that world. He is known as the 'Benelovent God' of that world, Ehito.

As for the Divine Mountain, it's a central place of the biggest religion of that world, known as the Holy Church. They also build their main building in the Divine Mountain. The purpose of them make that religion is to spread how great and benelovent their God is. The result of that were almost all of the humans believed in Ehito as their God.

However, the demons heard about the human's new religion and they felt insulted because of the humans claim that their God were the most superior beings than the others, even the God the demons believe. Because of that, the religions war between humans and demons started and still continues even after few centuries passed.

The demons have a lot of strength, but their populations were not that much compared to the humans. While the humans were far weaker than demons, their populations capable to balancing their enormous power, that's why there's no winner in either sides.

There's also a being known as demi-humans. They live secluded in a sea of trees known as Verbergen without any contact with any humans or demons or got involved with their war. If they strayed far away from Verbergen, sometimes they will be captured and turned into slaves. And if one of them able to use magic, they have to kill that demi-human.

But…nobody in Tortus knew that behind all of those, the main cause of all of those events was the humans 'Benelovent God', Ehito.

Both humans and demons didn't know that they prayed the same God but with different name. He even used his apostles and his faithful followers, the people of the Holy Church, to spread all of his 'teaching' and 'oracle' to every human in Tortus, even humans-demons war was caused by him.

Why is he doing all of that? It's simple. Anything for his own sick amusement, and Ehito is actually not a benelovent God, but an evil mad God. As of right now…

"It's getting boring."

He bored.

"After I ordered Alva to make all demons to tame monsters, humanities will be extinct earlier than I thought. It's really amusing to see the humans struggling against their new forces, but if it's happens, no more slaughters and bloods to watch. It'll be damn boring if peace happened again."

Monsters supposed to be a variant of wild animals that infused with heavily amount of mana which made them evolved. Though humans still didn't fully understand their biology, they were very powerful and capable to use magic, which made them very dangerous.

Until now there were very few people that could tame monsters. Even if they could be tamed, the tamer could only control one or two at most. Because of that, the balance has been shattered, and humans no longer had their number advantage against demons. Now humans faced against the crisis that threatened their existence.

As for Alva, he's the same being as Ehito, a spiritual being. But right now, he already possessed the body of a vampire who has a great connection with the vampire queen in their country and become a demon lord for the demons. Also, Ehito considered him as his retainer because he was created by him to make the humans-demons never stopped.

"Hmm… I need to find a new idea to make sure it's getting amusing again. I don't want another peace happened again. I want to see the slaughters."

Then he thought very hard for a new idea for his amusement, until he got something after thinking about his origin world.

"Let's see what another world is like."

Then he casted a projection spell to see a random another world. What he saw in the projection were a lot of skyscraper and a lot of things he didn't know, like the technologies he has a little knowledge about it.

But as an evil God, he never cared about it, because he found something irritating about the world he saw right now, even almost puked.

"It's too damn peaceful! There's almost no slaughter in that world." But an evil thought came to his mind. "But maybe, I can find someone who is stupidly heroic and easy to be manipulated in that world as a Hero in Tortus, and of course with his/her merry bands. After that Hero got stronger, I will possess that Hero's body and find my perfect vessel." After he said that, he laughed evilly. But then, he grumbled for remembering the past events regarding his perfect vessel. "Damn Dienleed for hiding my perfect vessel until I can't detect her. But too bad for you because your dead body has become Alva's vessel."

After he laughed madly after reminding someone's misfortune, he decided to see that world again using the projection he made. He quickly got bored after seeing every part of that world.

"I need to implement my game to this world after I got her."

With disgusted tone, he determined to change that world to his chess of death game soon. But something took his interest.

"'New World Online'? Isn't it like those illusion worlds made from magic but felt like real one, if I remember, virtual reality? Let's see what's inside of it. Hopefully it's interesting."

Then he changed the view of the projection to what's inside in 'New World Online'. At first, he's unable to see it because of the complex illusion of it. But, after pumped a lot of mana, he's able to see it.

When he saw the world inside of it, it's not as different as Tortus. He even saw some sort of war in there, even giant explosions of light, fire, and thunder. For the thunder, it's very flashy. The people in there even wore a lot of different kind attire and weapons, almost as if no one wore the same type of clothes or the same colors of it.

He couldn't help but felt giddy of it, like someone who has found a new toy to play with.

"I don't care if that's just a virtual reality, but I want this kind of people to join my death game!" Then an evil thought came to his mind. "I need to learn the concept of it, then tweak it a little, and send them to Tortus in random area without knowledge that when they die, they will die for real. And their real bodies become nothing but empty husk."

He laughed evilly again after he made a plan for them. After he calmed down, he decided to look for the peoples he found interesting for him using the projection he made.

While everyone in there were very interesting, he found eight most interesting individuals in there.

First, he saw an androgynous spellcaster boy with red eyes and curly red hair dressed in matching red-and-white scholarly gear, casting a lot of high-tier spells using his cube.

"That spellcaster able to use a lot of high-tier spells without sweat!? That cube might be his spellbook and maybe those spells only for a single usage. But I never knew about that kind of weapon, virtual or not!"

Then, he saw a male shieldbearer with brown eyes and short brown hair, died, but revived again and again without someone using resurrection spell on him. He also has large and muscular body covered in red armor, including his mouth.

"That shieldbearer able to resurrecting himself whenever he died, he's basically an undead! How is he able to do that!? Is it his equipment, or a skill!?"

Then, he saw the small twin girls with the same feature and attire, but with different colors, defeating someone who near their group with just one hit. One with black hair and green eyes and her attire has the same color as her hair, while the other has white hair and pink eyes and her attire also the same color as her hair. He also baffled because of their choice of weapons.

"Those brats able to wield giant hammer like it was some sort of stick, also in each hands!? Not only that, their attacks even able to kill someone in one hit!"

Then, he saw a woman crafter with long light blue hair reaching her waist and light blue eyes, turning her money into a useful item many times for her group. She wore alchemist attire with a goggle on her head.

"While crafter is the most boring job, like a Synergist, she's able to make it the most interesting job. I mean, how the hell she's able to craft anything with just converting her money!? Is it her equipment, or a skill!?"

Then, he saw a swordswoman in with deep, dark eyes and long, flowing black hair with trim kept tips, being styled quite similar to a hime cut, slashing everyone who near her group with her sword. She even has some sort of traditional vibe on her.

"Finally, someone who's not a complete freak like those five freaks. I don't know what kind of sword it is, but her skills in sword are very deadly. If I send her to Tortus, she might be become the strongest Swordsmaster in there."

Then, he saw a girl with ash brown hair tied in ponytail and ash brown eyes, evading every attack who targeting her.

Her attire consist of a gray turtleneck, extended until her jeans, noticeably cut in the sides, which exposes her body curves, with a silver breastplate covering the entirely of her ribs, and additionally her clavicle. She even wears a blue scarf which cover the entirely of her neck. As for her lower half, she wears extremely short jeans, which is accompanied by a white belt with a golden buckle. She wears a pair of dark grey boots that meets her knees in height, also wearing socks striped with blue and black, which reaches until her lower thighs.

"Another freaks! This time an evasive freak! How is she able to evade any kind of attacks without scratch!?"

And finally, he saw a shieldbearer girl with black hair that extend beneath her chin, with a small ahoge, and dark grey eyes, didn't feel any pain, even though she's been attacked. He also saw that she can turn her hair color into blonde, sprouted angelic white wings, and a halo on top of her head. He even saw her armor able to turn into heavy weaponry which can shoot a lot of lasers. And he also saw her able to turn into a giant monster with four arms.

Her attire is a black suit of armor with red accents. It has a crest of a flower, an image of a rose, on the armor's chest piece. Underneath of it is a red leotard as well as matching gloves and thigh high stockings.

"I don't know how to describe her, but she's an irregular…a monster. She'll become the biggest threat for me if she's got sent to Tortus."

After he has seen enough of it, he laughed evilly, this time much louder.

"It's decided. I'm going to tweak a little of that virtual reality, lured those unfortunate individuals to join my death game in Tortus. I don't mind if one of those freaks got lured by my trap, but I don't want that shieldbearer girl who got lured by it."

Then he smirked evilly while watching everyone in 'New World Online', even though he doesn't have a physical body.

"I hope you can entertain me in my death game soon."

Before his tweaks got implemented in 'New World Online', he decided to observe it again, until he screamed hysterically because the swordswoman who he thought not a complete freak has become one of those freaks thanks to her new sword.

In another world known as Earth, there's a first case of someone who got brain-dead after playing a VRMMORPG known as 'New World Online' and it happened few days after the fifth event of that game. Then the case got bigger after the sixth event of that game.

The developers apologized to everyone for what happened to them, even though they still didn't know what caused them to be like that. They tried their best to find the bug of it and found a quest that they never implemented to that game, but they unable to delete that quest. They also thanked the anonymous player for telling them about that quest. Because of that, they decided to post the news to everyone about 'New World Online' still safe to be played as long as they not attempting a certain quest.

No one, even the developer, knew that it was the mad God from another world ploy to find a new source of amusement for his sick game.

Sometimes later, a lone person walked to the quest board to saw the quests posted in there. Then that person found an interesting quest which that person read it.

"'Five adventurers needed to become additional training instructors for the divine heroes from another world. Please help us to train them for their quest to defeat the demons and save the humanities. Requirements: At least green ranked adventurer or higher. Payment: 10000 luta per day. By Heiligh Kingdom.'"

After that person read the quest, a sad smile formed on that person's face and muttered something.

"I see, another victims, huh. But this time is not from the game, but real world, Earth."

Then, a man voice called that person.

He has short trimmed brown hair and yellow eyes with muscular figure and a greatsword sheathed on his back. He only wears a blue vest, long black pants, and black boots. He might be looks young, but he's far older than his looks.

"Hey, are you going to take that quest?"

That person turned to him, who has sit on the chair with a giant mug of beer on the table where he sit, and answered his question.

"I don't know. What about you?"

"Pass. I might be a white ranked adventurer, but I'm not good at teaching stuff, no matter how much you pay me." After a short pause, he suggested that person regarding that quest. "How about you take that quest, you have the requirement needed for it and you also have a reputation as an adventurer, right? It'll be a great experience for a youngster like you."

After thinking long enough, that person sighed after that.

"I guess I'm going to take it. Besides, I'm curious about this 'divine heroes from another world'." Then that person walked to the guild receptionist to take that quest. But suddenly, that person turned to him. "Please tell your daughter I say hi to her."

He nodded while smiled gently at that person and replied.

"Yeah, and good luck, XXXX."

A/N

A new BOFURI x Arifureta crossover story. Don't worry, it's not a rewrite of my first story.

The reason I decided to write a new different story because I already thought about it in my mind two days ago and decided to write it. If you like it, I'm going to continue it.

If you don't know who Alva and Dienleed, read Arifureta LN or its wikia (if you ready to be spoiled for the latter).

I'm going to make a poll about who's 'that person' in this prologue. It's one of the member of Maple Tree guild but not Maple herself because I already planned for her in this story. The choices are:

1. Sally
2. Kasumi
3. Kanade
4. Kuromu
5. Izu
6. Mai
7. Yui

The poll is open until two weeks.

If you have any questions, input, or suggestions, just write it in review or PM me. Also, no flames or spam please.

Thank you.