Revenge with the Power of the Final Boss

The Black Serpent That Devours the World, or as those who know its body color call it, The Black Serpent That Devours the World.
The final boss of the original story appeared before me, still a 10-year-old. Well, it wasn't exactly an appearance—it was more of an error in how it manifested.
‘Sharp tendrils are visible, but no form is seen?’

The form of The Black Serpent That Devours the World was nowhere to be seen. Instead, the tendrils that seemed to represent its power were visible. The sharp tendril that had obliterated Rupert the writer had emerged from thin air.
"So, you’re the final boss of the original?"
In fact, calling it the "original" was a bit ambiguous. It could be called the "original" since it referred to what had originally happened, but that event wasn’t really a fictional story—it was supposed to be something that happened in another world.

That’s right. Reincarnator. Your name is Baek Seo-jun, is it not?
"Yes. Baek Seo-jun. That’s my name."
Kim Ho-cheon is dead. My identity was largely based on Kim Ho-cheon, but now, I was Baek Seo-jun.
I was the one abandoned pitifully by my biological parents, sold to villains, and thrown into hell.

Baek Seo-jun. Yes, Baek Seo-jun.
As it spoke, the tendrils created by Ramisa seemed to hesitate, as if it were thinking about something.
"What are you thinking?"
I’m thinking about how to view you. Hmm, you are human, but a reincarnator. You could be considered a hope for me... but you’re still just a human.
I could almost understand what Ramisa was saying.

‘To an external entity, humans are insignificant.’
It seemed that, due to the issue with The Fox That Devours Worlds, I might be necessary to it, but exactly how I was needed remained unclear.
‘I should be cautious.’

I couldn’t be certain how useful caution was to an external entity, but the fact that it wasn’t attacking me immediately and was considering how to treat me seemed like a good sign.
It wasn’t treating me as just a worthless human without thought, meaning that perhaps it valued my will in some way.
"So, you need my existence as a reincarnator, right?"

Ramisa responded to my words.
Yes.
"Then wouldn’t it be better to tell me outright? Or, do you need to ignore my will and force me to follow you?"
No, that’s not it. A reincarnator like you has become strong enough to kill Terenity. If I harm you, I might face retribution eventually.
"I see."
Even though Yoo-cheon wasn’t by my side, having him as a friend after 10 years was reassuring.

He had killed one of the strongest external entities, Terenity, and although he didn’t yet realize his own power, he would eventually.
‘If it harms me, Yoo-cheon will be able to take revenge. I never thought that just his existence would be my backup.’
However, I did feel guilty for using my friend’s name to survive. I also felt bad for the friend who had to die for me to get here.

‘Sorry, Yoo-cheon. I’ll apologize later.’
I silently apologized as I thought about revenge. I would get revenge on Baek Hyung-won, Kim Yoo-jung, and the villains who threw me into this hell.
For that revenge, I had to survive by any means necessary.

"So, what do you want? What’s your plan?"
It’s not a difficult task. What I want is survival. The Fox That Devours Worlds will kill me if it finds me, so I’m hiding here in this rift... but that will only last so long.
"So?"
I want to make a contract with you. You have potential. If you don’t gain my power, you’ll continue to grow stronger. And if you meet the one who killed Terenity, you might become even stronger than me.
I was amazed that Yoo-cheon had become that powerful. But I didn’t think Ramisa would lie to me, so I was curious about what the final boss of the original story wanted from me.

"So what kind of contract do you want?"
It’s not difficult. I will pass my power to you. The essence of your soul is growth. The human soul can transcend worlds, and because it has received the wishes of a world, it holds potential. If my power is added to yours, you will grow faster and become infinitely stronger. So, protect me from The Fox That Devours Worlds and others. If you have my power, you will be undetectable by other strong beings. I, too, will be safe from their detection.
It seemed that Ramisa wanted to give me its power in exchange for hiding.
"And if I protect you? What happens next?"

What happens next? You want me to not consume the world like I did before, don’t you?
"Exactly. And can you fulfill other requests I might have?"
Of course. If you ensure my safety, I’ll fulfill your wishes.
"So, we can be allies, then?"
Allies? Hmm, yes. You are an equal partner. An equal ally.
It seemed that Ramisa had decided how to view me. It didn’t seem to regard me as an insignificant human, nor did it treat me as just a tool. Instead, it saw me as an equal partner.

It didn’t show any arrogance toward me. In fact, it seemed indifferent, as though I was simply a means to an end.
After all, after spreading mana throughout the world and consuming it, it was only a step toward strengthening itself.
There was no malice or arrogance, only a cold, indifferent practicality.

"Show me your form."
"I understand."
Then, instead of the tentacles, someone appeared in the empty space where there was nothing.

What I had expected to be the huge black serpent from the original story was instead a stunningly beautiful woman with black hair and golden eyes.
"Ramisa?"
"Yes. Isn't this form easier to talk in?"

Ramisa said with a wink as she looked at me.
"Well, but don't you think you should wear clothes?"
I suggested she put on some clothes first, considering she was completely naked without even a thread of clothing.

Since my body was still that of a 10-year-old, I didn't have much of a reaction, but if this were in my past life, I would have reacted automatically.
"Is that so?"
Ramisa tilted her head at my comment and nodded.

"I see. Humans are like that. Hm, I suppose something simple would be good."
She then created a black dress and wore it, sitting down in front of me with a neutral expression.
"So, the deal is as I mentioned earlier. I will give you my power, and you will grow that power. And I will follow your will, so you must protect me to the best of your ability and treat me as an ally."

"Is there any problem with those terms?"
I asked if there was any issue, and Ramisa responded.
"There is one. I'll need to stay here for about 40 years."

"...40 years?"
"Yes. The flow of time in this world and the one you were born into is the same, so after about 40 years, you should be able to return."
At those words, I recalled The Fox That Devours the World and asked,

"While I’m here, how will The Fox That Devours the World move?"
"Your world will likely be destroyed. So after receiving my power, I suggest you forget about your world and head to the world where your friend has been reincarnated. I don’t know the exact location, but if you accept my power and grow it, you'll be able to find it."
In other words, the world I was born in would be destroyed.

"Is there any chance Baek Seo-jin could win?"
"None."
Ramisa stated it firmly.

"If I let my guard down, maybe it’s possible. But even if the world itself aids you, there is no way to stop The Fox That Devours the World in the world you were born in."
In other words, the world was facing a much greater threat than in the original story.
'I could pretend I don’t care, but...'

To be honest, I had no strong feelings for that world. It wasn't as if I had cherished memories there.
But was there truly no possibility of saving the countless people living there? And if there were, could I simply leave them to their fate without feeling anything?
'And my revenge too.'

I wanted revenge. Could I be satisfied if the ones who sent me to hell simply died without any consequences for themselves?
'Impossible.'
Both of those choices seemed impossible for me.

"It seems like you want to save the world," Ramisa said.
"Yes."
"I personally do not recommend this method. After accepting my power, I would have preferred that you ask me to be hidden and protected, taking me to a safe place."

Ramisa, revealing her personal agenda, added,
"But if you go there, you will inevitably clash with The Fox That Devours the World. Even if you grow stronger, the odds of winning are uncertain. I do not want to risk such an adventure."