Spoilers: This FanFiction story contains information from the Series (primarily from Light Novel 20).
This is still a custom story of what I think could've happened. It may or may not be correct to what the Series is about, and possibly steer off into its own thing. Although I do try to be decently accurate.
Style Table of Contents:
Italics: Thoughts or similar.
No Italics: Speaking outside of thoughts or similar.
"Rimuru Tempest speaking."
[Ciel speaking.] or [Unknown Voice speaking.]
{Mysterious Voice speaking.}
'Mysterious Being speaking.'
Disclaimer: I don't own That Time That I Got Reincarnated As A Slime.
Chapter 1: The Mysterious Voice in The Void
Rimuru Tempest is a transcending being, harboring bluish-silver hair and golden eyes that radiates a breathtaking image of divinity. A golden-blue aura cloaks his body becoming a beacon of light in the immense void where he now resides. The Slime that has taken a humanoid form has managed to escape The End of Time and Space, foiling Feldways plans to isolate it. The human-like being then proceeds to vanquish his adversaries and devour two of them (an Awakened Feldway and an Evolved Ivaraj).
A Manas (a digitally natured spiritual life form) named Ciel suddenly speaks into Rimurus mind with a robotic voice sounding a bit like a female human:
[Master... Are you ready to wake up?]
"Ugh... I suppose, how long have I spent sleeping Ciel?" Responds the divine being waking up while rubbing his eyes and letting out a sleepy yawn.
[Report: The user Rimuru Tempest has entered sleep mode and stayed asleep for a millennium.]
"What...!? Why did you let me sleep so long!?" Rimuru asked out loud, levitating in space with a shocked facial expression.
[I... I Didn't want to disturb your slumber, Master, my apologies. My original idea was just to let you be, but I figured you'd like to wake up at some point as well... Such conflicting thoughts... Such conflicting feelings...]
"I... See," Rimuru thought while taking a look around. "Nothing... All I see is nothing, well except for The Void, although that technically still counts as nothing right?"
"Ciel?"
[...]
"Are you mad at me or something?"
[Negative, you are correct, The Void is technically nothing, what would you like to do now Master since you are awake?]
"Umm, hmm oh! I know how about visiting my friends?"
[Time would have to be turned back a bit, say... Nine hundred and ninety-nine years...]
"Why?"
[...]
"Why..." He asks out loud with annoyance in his voice.
[Your friends... Despite the defeat of our enemies... They... P-perished, Feld—] Rimurus explosive aura erupts from deep within, stopping Ciels explanation. "WHAT!? HOW!?" Screamed The Slime, that looks like a human teenaged girl with bluish-silver hair. The Void starts to shake a bit from the sheer aura emanating from him, slowly destabilizing bit by bit.
[Master! Restrain yourself please!] Exclaimed Ciel.
Upon hearing the Mana's concern in its voice, he calms down and conceals the aura surrounding himself, but tears start slowly trickling down his face. The Void begins to re-stabilizes as well. "P... Please continue Ciel, I-I am so... So sorry..." Rimuru sadly thought, looking down feeling immense shame.
[...Master... You have nothing to apologize for, Feldway did some kind of delayed timed annihilation attack, most likely utilizing the Ultimate Skill Armageddon and has adjusted it somehow. It struck after your effortless victory... I didn't see it, the skill's power hid itself in your magicules surprisingly well, and all of a sudden one day started to tear through your body, dangerously close to destroying your very soul.
It would have even spread throughout your soul corridor as well. I... I had to activate emergency protocols and cut off all connections that have been established via the soul corridor and put you into sleep mode to regulate the unstable magicules within you. Otherwise, you would have died... As an unfortunate consequence... When you were surrounded by all your friends and subordinates and everyone else... They... They couldn't handle the violent instability of your magicules, which have been infused with Turn Null, resulting in a catastrophic explosion coming out of your body.
The World got destroyed and the Universe turned into darkness, all life nullified... All potential reincarnations have been nullified as well. The sheer mastery of Turn Null has disrupted even the cycle of rebirth that the True Dragons and the Primordials use.]
Upon hearing all of this, Rimurus' once brilliant golden eyes go lifeless and cold, tears stop flowing down his face as he clenches his fists and whispers angrily out loud: "So, it was all my fault... I wanted to gain power near the end, to protect my ideals, to protect my friends, to protect my subordinates, and to protect those who were allies with me, and to defeat those who threatened all of it. My very own power getting corrupted and thus killing and annihilating everything, and everyone..."
He looks up then yells: "DAMN IT! WHY!"
[Master...]
"Will it work Ciel? Will going back fix everything?" The Manas master asks, gaining composure once again, floating in place majestically while staring straight ahead. [Unknown according to your memories the skill seems to have been activated sometime within that year... If calculations are correct it went off during a festival, unfortunately it appears that the skill may have time tamper protections as well, in other words it utilizes a randomized time variable... Meaning even if you were to go back in time to the day it happened, it may not even happen on that particular day again, and the skill is only visible once it activates.]
"That bastard... Feldway..." Rimuru angrily says aloud, punching downwards sending an immense wave of energy infused with his furious rage. It sends a ripple throughout the whole universe.
[Master!]
"It has to be okay! I... We'll figure this out r-right?"
[I don't know...]
{Maybe I can help out...} A mysteriously ominous voice echoes out from The Void and then manifests itself into his mind.
[Warning! Do not listen to this voice! Deceptive intent detected!] Ciel states in a freaked-out voice.
[...]
{...Oh my, already judging me before I can say much else... Ciel.}
[How do—]. Before the Manas could say anything else, Rimuru interrupts and mentally asks: "How can you help me?"
{I have a simple question or two to ask you... Rimuru Tempest...}
"O-Okay? What are they?"
[Master no!]
"Ciel... Be quiet please..."
[...]
"I am sorry about Ciel, my Manas can be a bit paranoid about me haha."
{...Anyhow what do you recall about what your Manas Ciels word's were from earlier?}
"Oh? Umm, about Feldway?" Asks Rimuru tilting his head perplexingly.
{Yes...} It answers in a calm non-ominous way.
"Right, let's see, Ciel said basically that Feldway adjusted the Ultimate Skill: Armageddon and he used it as a time based attack against me."
{Correct... Now let me ask you this. Who else do you know that can adjust Ultimate Skills?}
"Ciel."
{Correct again! Now let me ask you another question... Do you think it would do anything, I mean anything to protect you?}
"Um, yea? I trust my partner... What are you getting at?" He asks slightly perturbed.
{Another question... Would it seal someone's potential to evolve an Ultimate Skill if it was a risk to you?}
"Oh yeah, I think Ciel blocked off Shions potential to gain an Ultimate Skill."
{Correct!}
{Another question, Do you think Ciel really needs your permission to do things all the time?}
"I am not too sure, I would think so normally, I know that my partner prefers to ask though, but if absolutely necessary probably could do its own thing."
{Normally...}
{...}
"Umm? Are you still there?"
{Yes! Now another question, possibly the last one, since you seem to be getting a bit... Impatient. Do you believe that your skill or should I say Manas would adjust another enemy's skill like Feldway's; to execute a plan that involves eliminating all possible threats? A plan that included your enemies, allies, even your very friends, and even... even the children...}
[...]
"I-I don't know... C-C-Ciel? Y-you w-wouldn't do-do that r-right? You're my partner, my most loyal and trusty partner..." He trails off, a sudden overwhelming feeling of distrust starts to take root in his mind.
"CIEL!" He yells out with immense anger.
[...]
"Explain! Now! That is an order!" Coldly demanded Rimuru crossing his arms and glaring, but second thoughts occurred: "You know what! Never mind! I don't think anything you'd have said could possibly justify your actions!" The bluish-silver haired teen said, pointing a finger at himself then towards The Void; crying out loud emotionally shaking: "Who are you! What are you!?"
{I would like to say a few words...} It answers, with a vaguely familiar tone of voice.
"Go on... Not like it is going to mean anything, anyhow..." Rimuru with a depressed tone of voice trails off going on his hands and knees looking straight down trying to keep what little composure he has left.
{Oh dear, Sir Rimuru. It certainly is not... True.}
Rimuru didn't hear that last word, only the words before it mattered significantly, so much so that he grabbed his chest near the heart with immense emotion.
"Those words... That voice... Could it? No, but it-it sounds just like that person. When I was in the process of forming the Jura Tempest Federation..." He couldn't fathom that possibility, but before he could keep going the voice interjects his thoughts: {Besides who else is going to be your first and best and most favorite of secretaries?} Rimurus' eyes opened wide and he cried out for the person that would say those words: "SH-SHION!?"
{Yes? Sir Rimuru.} The voice replied mentally in a calm gentle manner, materializing out of his mind and sounding real close, he could feel a presence close by. The bluish-silver haired teen refuses to look up and says with immense regret in his heart: "I want to believe it... I really-really do! I-I can't look up... I am just too scared to!" Rimuru blames himself for what he thinks has been done...
Killing Shion with his own magicules, his own two hands even if it was Ciel's plan that ultimately led to her demise. As those thoughts got pondered, a warm gentle finger just underneath the chin was felt, which slowly lifted his head up, he didn't resist. As soon as Rimuru sees the figure it moves back a little bit and kneels before him, looking straight into his eyes. There was no mistaking it any more, it was indeed Shion showing a sheer will of spirit burning brightly within her eyes.
Upon staring at them the bluish-silver haired teens mind freezes for a full minute, with some more tears dripping down from the sides of the face, Rimuru suddenly wipes them and clenches his fists with a renewed sense of vigor, snapping out of his emotional crisis and transforms into his slime form. Shion then stands up and sees the ruler of monsters float towards her, The purple-haired ogress then grabs the slime, placing it just below her bountiful chest.