The age of my reign may have dimmed in the other world, but don't get it twisted. I didn't fall. I simply woke up in this flimsy human shell again. Yeah yeah, Mikami Satoru, office drone, stabbed on the sidewalk like some background extra. Pathetic. Embarrassing. If someone brings it up again, I might actually combust. But I'm not dying like that twice. Absolutely not. I still have her. The one who pretends she's all logical and emotionless. The one who huffs in my head every time I call her by name. Ciel. She's an manas , my partner, sure, but she's also my constant, terrifyingly perfect partner who nags me about "inefficiency" every three seconds. And I... ugh, fine, I rely on her. A tiny bit. Not that I'd say that out loud. Ever. Trapped in a world with no magicules, no nation of monsters to bow their heads, no absurd overpowered allies... all I have is this weak, annoyingly mortal body. So I'll reshape it. Break it. Rebuild it. Make it something that can keep up with the monster I used to be. My training is brutal, intense, and yes, I complain about it, but shut up. It's not like I'm doing it because she told me to or anything. If the world thinks it's peaceful, that's its own delusion. While everyone else sleeps, I grind myself past my limits. I'll surpass even the version of me that was crowned Demon Lord. I'll make this pathetic reality kneel without even knowing why. And if I chant a few chūnibyō spells under my breath? It's called preparation. Not cringe. You wouldn't understand. I'm Satoru, Rimuru, whatever name the universe tries to chain me with. And I'm just getting started. Not that I care if anyone recognizes it or anything. Hmph.

Solo Leveling x Rimuru

"What if Rimuru Tempest had been born not as a simple slime, but as the lost son of Veldanva, the Star King Dragon?" Sealed away for millennia, Rimuru awakens in a world that has long forgotten his existence. Half-human, half True Dragon, he inherits the power of the gods and monsters alike-[Raphael, Lord of Wisdom], [Gluttony], [Void], and the legacy of his father. But his return shakes the balance of nations, drawing the eyes of the Demon Lords, angels, and ancient enemies that once defied creation itself. Alongside allies old and new - Hinata Sakaguchi, Luminous Valentine, Shizue Izawa, Chole Aubert, Elmesia El Ru Sarion, and even his family of dragons - Rimuru must forge his own destiny. Not as Veldanava's shadow, but as the one who will unite dragons, demons, humans, and gods under a new banner. This is not the story of a slime. This is the tale of the Dragon King.

After evolving to a True Demon Lord Rimuru decided to spar with Veldora to get a hang on his new power but something happens and lead to his further evolution to a True Dragon

what would happen if a young teenager named Harumi Sora got reborn as mikami satoru's daughter before he got reincarnated as rimuru in tensura and have the same name she had on her past life and what if great sage brought her along with him and in the process making her a true dragon and a slime at the same time? now let's see what will her journey with her father who was now a slime while also acquiring a big brother and 2 big sisters along the way

What if the all of tensura characters reacted to Slime Adventures and helping the true dragon's problem. What if Veldora's sisters were also trapped inside unlimited imprisonment? They went to go stop Veldora but they got trapped by the hero. Guy and Rudra never went to go and save them or break them out; however, Milim sometimes visits them. Years later, a slime appeared out of nowhere, born from their magicules, and helped them out. Join as everyone react to the true dragons watching Rimuru's journey into a demon lord and become one of their own become their family.

Ten years after the end of the Great Tenma War, the world is finally at peace. Rimuru Tempest has become something beyond comprehension-a godlike being with uncountable power, unlistable skills, and a divine weapon forged from Genesis-class blades. And yet, buried beneath his calm smile and mountain of paperwork lies a quiet, aching regret. He couldn't save Shizu. He couldn't reach the Ogres in time. Despite all he's built, those moments still haunt him. But when a single question leads to an impossible answer, Rimuru realizes one thing: With his current power, even time itself is no longer a limit. Now, Rimuru travels back to the past-to rewrite his story, save the people he loves, and create the perfect future he once dreamed of. This is a story of second chances, deep regrets, and a god who still carries the heart of a slime.

In this story in another timeline, Rimuru Tempest found a way to save Shizue and things went well they got married and had a child. However, things did not have a happy ending he tries his best to protect them when the whole world is being destroyed and Rimuru and all the monsters try to save themselves with help from Elyun and Keval partly and some adventures to make a portal to another world/timeline. However, only two people could go in so Rimuru lets Shizue and his daughter go to new timelines where can live happily. However, it seems both mother and daughter landed in a timeline where Rimuru evolved into a demon lord trying to resurrect the dead of the monsters. Join both mother and daughter to enjoy their second chance but the one they call husband/Papa has become a demon lord in their new lives. Rimuru has a second chance with Shizue that he couldn't save in his timeline. Join them if they change the future and live peacefully and what new adventures await them. Ok, there are some fanfics out there where Rimuru saves Shizue and sends her daughter to a new timeline but, What if Shizue comes along with her and lands in Rimuru's evolution into a demon lord what happens then?

A what if Rimuru x Milim story with action I guess

Satorou Mikami was a normal guy with a mundane life until all of it changed at once. <It hurts. There's so much blood> [Confirmed: Pain nullification aquired. Building a body that does not require blood.] <What a terrible way to go. How old am I and still a virgin. If it's true that turning 30 and still being a virgin gives you wizard magic, then I must be a great sage> [Confirmed: aquiring the unique skill {Great Sage}... successful] <I never got to finish that novel about the dragon that stole the world tree. If I were that dragon, I'd steal all the ladies.> [Confirmed: Unique skill {Plunderer} aquired] <Being a dragon would be so cool. What a shame the character was too much of a pacifist. I never got to the part where he actually turned into a dragon. He should have been so much more aggressive, like that demon he fought.> [Confirmed: The individual's constitution will be rebuilt according to their desires. Aquiring True Dragon form... unable to aquire a True Dragon form. Attempting Sub-dragon constitution... failed. Attempting Dragon form... successful. Aquiring Spiritual form... successful. Applying demonic constitution... successful] <If I was born earlier, would that have made a difference in my life?> [Confirmed: Attempting to locate earliest possible point for incarnation... No compatable point has been found in the cardinal world. Searching for alternatives... Successful. Individual will incarnate into the underworld.] <What is happening to me?> [Notice: Individual has aquired a new species form as a false dragon.] <What is that voice?> [Notice: This is an effect caused be the Voice Of The World.] <Shut up... can't a guy die in peace?> Upon waking, Satorou found himself in an unfamiliar place... and he wasn't human anymore? He got stabbed and now he's in another world? And what does demon constitution mean? False dragon? What does that even mean?