It’s a new day, the sun is rising higher and higher into the sky. It’s still quite early, around 8 o'clock, approximately.

Right now, Other Rimuru is hard at work in his office, sorting through piles of paper, dealing with the aftermath of the Charybdis event and resuming normal operations.

He is in his slime form, sitting on his desk, using his slime tentacle thingies to shuffle through the papers.

*Bang!*

I kick open the doors to his office, a cheeky grin on my face as my white hair drifts in the wind.

Rimuru- “HEYO!”

Other Rimuru- “*Screams*”

Rimuru- “Ahahaha! How are ya doing ol friend ol buddy ol pal!?”

I laugh while walking towards him.

Other Rimuru- “*Sigh* Please don’t do that, it’s not good for my heart…”

Rimuru- “Don’t worry, we don’t have physical hearts!”

Other Rimuru- “That’s not the problem here…”

Other Rimuru’s slime body sinks in exasperation. I just chuckle to myself.

Other Rimuru- “Where were you last night anyway? You and your companions just kinda… disappeared, after the party.”

Hmm… that’s a good question. I honestly can’t remember. It’s like Author made another time skip…

Rimuru- “Uhh… Not important.”

Other Rimuru- “… Riiight… where are your companions anyway?”

Rimuru- “Hmm? Oh, Illya and Mikoto are hanging out with Shion, Shuna, Milim, and the rest. Which reminds me, we gotta go!”

I grab his slime body and run out of the room.

Other Rimuru- “Wha- Hold on! Where are we going!? Why!?”

He shouts as I run down the hallway.

Rimuru- “Not important!”

Other Rimuru- “It’s plenty important!”

Rimuru- “You can’t escape, Other Rimuru!”

Other Rimuru- “Stop calling me thaaaat!”

Later…

Other Rimuru- “So… where are we?”

Other Rimuru asks while in his human form. He looks around, finding himself alongside me surrounded by trees. When he looks up, however, he sees the sky fragmented and shattered like glass.

Rimuru- “The Mirror Dimension. It’s my personal dimension.”

I casually say while kneeling down and writing a rune circle on the ground.

Other Rimuru- “You have a personal dimension!?”

Rimuru- “Yeah, I made it. Took a lot of work. Well, that was a while ago… I can make one for you too if you want?”

Other Rimuru- “… Um… No, I'm good… I mean… maybe?”

Rimuru- “Come on! Don’t need to be shy! What do you want in it? Rainbows and sparkles?”

Other Rimuru- “Preferably not, thank you…”

I continued to joke around a bit while working on the runes.

In the end, I did actually give him his own separate dimension. I was joking at first, but I thought “eh, why the hell not, it’s not like I’ll be here often” so I just gave it to him. But there’s a little twist to it that should also prove extremely beneficial down the line.

I’ll give you readers a hint. The activation words are “ID Create”.

Yes, it’s the Instant Dungeon (ID) from The Gamer manhwa. Saying the keyword will pull Other Rimuru into an alternate dimension that’s kinda like the Mirror Dimension.

Except, you know, without the special fragmented mirror/glass effects. That one is exclusive to mine.

He can also pull anyone and/or anything else with him, but they have to have his permission first.

Using [Codex: Illyasviel] to fiddle around with this world’s World System, I cranked up the natural spawn rate of monsters in the ID to insane levels. For comparison, the natural spawn rate of monsters in the wild is around 100, the spawn rate of monsters in the ID is over 9000.

Yes, that was a reference.

Although I made sure to limit the spawned monsters to non-sentient ones. I'm sure Rimuru wouldn’t feel comfortable killing goblins, ogres, and the like. Instead, knight spiders, giant ants, ribears, and gingers will spawn.

Rimuru- “… You know, the ones who don’t think and only act on instinct. Monsters with no soul.”

Other Rimuru- “Hold on, what do you mean by ‘gingers-‘”

Rimuru- “Not important.”

(A/N: This is a joke, I have nothing against redheads lol.)

*Snap*

And with a snap of my fingers, half the universe dies- oops, lemme just redo that…

*Snap*

*Cough*

*Snap*

And with a snap of my fingers, I bound the space to Rimuru’s soul.

Other Rimuru- “What were those three snaps for?”

Rimuru- “The first one was a mistake, the second one was me fixing that mistake. The third one was binding the ID to you.”

I look Other Rimuru in the eyes with a look that said “don’t ask”. Thankfully, he listens.

Rimuru’s ID only works in whichever universe he’s in, unlike my Mirror Dimension which is spreading out throughout the multiverse.

I got an idea, and so I acted on it. I turned the Mirror Dimension into some kind of spatial virus and set it loose, causing it to “infect” world after world, universe after universe, expanding into the infinite void. Once a universe is “infected”, a Mirror Dimension becomes available there.

… And that’s it. It does literally nothing else.

Well, Illya did change it a little, by making any books in an “infected” universe to be added to Avalon’s library, but that’s mostly her idea.

Other Rimuru- “… So, I've been wondering for a while… what are you doing?”

Other Rimuru asks me, breaking the long, awkward silence that appeared during my monologue.

I look up to see him looking at the rune circle I'm working on with a confused expression.

I look down at the headache-inducing circle of constantly altering runes. None of the runes stays in a single form as they constantly change forms, softly glowing in a silvery light.

In a word, it is Unworldly. It isn't something that can be comprehended with a human mind, and if you try, you’ll only overload. I guess only someone like Mikoto can completely understand what this rune circle can do. Maybe Veldanava too.

So it isn't really a surprise that Other Rimuru’s [Great Sage] can’t tell anything. Maybe [Raphael] can? If not, maybe it can at least decipher the general concept of the circle.

I look at the rune circle with an unreadable expression. I then look back up at Other Rimuru.

Rimuru- “Well, I WAS drawing this circle to boost your [Great Sage] skill, maybe evolve it into an Ultimate Skill while I'm at it, and maybe even boot you into the ranks of Demon Lords.”

Other Rimuru- “HAAH!?”

Rimuru- “But then I realised I'm a dumbass and I could just GIVE you an Ultimate Skill and be done with it through the World System.”

Other Rimuru- “You can do WHAT through the World System!?”

Rimuru- “Yeah, I already hacked it to fiddle with your ID. Hahaha! Silly me!”

I say while scratching the back of my neck.

Other Rimuru- “…”

I don’t hear a response. I look over to Other Rimuru and understand why.

*OtherRimuru.exe has stopped working*

Well pooh…

Half an hour later, after Other Rimuru recovered…

Other Rimuru- “Ughh… my head hurts… I never thought I could feel this way after becoming a slime…”

Other Rimuru complains while clutching his forehead. He is currently sitting on the ground in his slime form while I'm still standing looking down at him with a slightly concerned look. Does he even have a forehead in that form…?

I rub my finger under my nose.

Rimuru- “Yeah, stuff like this happens from time to time. I always chalk it up to bullshit anime logic.”

Other Rimuru- “… That… surprisingly makes sense.”

Other Rimuru looked like he had some choice words but decided that it’s not worth it.

Other Rimuru- “So… Why were you trying to boost [Great Sage] again?”

He didn’t mention the forceful evolutions… probably for his own sanity.

I answer him like it’s the most obvious answer in the world.

Rimuru- “It’s to release Veldora, of course!”

Other Rimuru- “…”

Rimuru- “…”

Other Rimuru- “… Ok.”

-----

Name: Rimuru

Race: Origin Slime

Protection: Crest of Space

Title: Highest Tier Spirit, Leader of the Monsters, Onii-chan, King of Avalon, Master of Headpats, Procrastinator King, The Nutcracker, socially awkward cringe slightly chuuni slime, True Dragon Slayer, Sensei, World's Strongest, Overpowered to a stupid degree, Mikoto's Equal, Non-Virgin

???: [Codex: Illyasviel]

Ultimate Skills: [Yahweh, God of Creation], [Odin, God of Runes], [Azathoth, God of Void (Alternative)]

Equipment: Yamato - Genesis