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English
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Part 1 of The Good Dimension Timeline, (Main Story and Oneshots!) , Part 3 of Lumini / Cosmos fics!
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Published:
2026-06-23
Updated:
2026-06-23
Words:
1,419
Chapters:
1/?
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8
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16
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128

Under The Stars [You Burn Brighter Than My Heart.]

Summary:

Cosmos winced as the tree before him came undone, falling to the ground with a large crackle that rang out throughout the place — he only hoped the action hadn't disturbed any wild life.
He was frustrated, yes. 
He never felt like this before.
Sure, Helpy used to be able to get his heart fluttering — but this? This was a whole other feeling threatening to consume him whole.
And like the idiot he was, Cosmos found himself giving in to the demand, rather than fighting back the void wrapping around his body and pulling him into territories he never thought he’d cross.
But that wasn't the worse of it.
At least with Helpy, there was a chance that they could love him back. A chance that they could have a happily ever after.
Gemini? Cosmos laughed at that thought — the idea of his feelings being mutual was like the concept of a pig flying in the air.
----
OR: Cosmos found himself in a situation he'd never thought he'd be in again. In love.

From the book 'Cant Fix Your Family? Go To A Whole Other Dimension!' starring Cosmos and Gemini. You CAN Read this without having read the other book, but it may be confusing!
Not canon to the other book.

Notes:

Hellooo! I hope you like this, i am a beginner writer so apologies if any of my writing is hard to read! Advice + Criticism is appreciated! I also love comments!
Info you'll need if you havent read the main book:
Cosmos essentially got trapped in a 'good dimension' where every villian got redeemed, basically just.. happiness. He ends up getting adopted by them, and the Astrals in that univesre decide to train him alongside the Lunar of the universe, hence the mention of Lunar you'll see in the story! Thats basically ALL you need to know!
IF you came from the main book/know the main book. Regarding the Trans tag, if I do decide to make Cosmos a transwoman, it is something that most likely will not happen in the main book unfortunately, but is it a possibility!
I made this book because I LOVE Lumini and since we've just started the romance arc between Gemini and Cosmos in the other book, I realised i wanted to write them TOO Badly.. and since I didn't want that to get in the way of the lore and plot of the main story, I decided to create this story as a "timeskip / what if" type of situation, taking place around the time they get together so I can write alllll the Lumini i want without it getting in the way of the main book!

(See the end of the work for more notes.)

Chapter 1: Oh, how beautiful you are

Chapter Text

Training had gone like always.

Get up, help in the daycare, wait for the designated time, get to where he was needed — and begin training.

Lunar would often times join him — but he had long since ‘graduated’ from training in a sense, leaving him alone with Gemini.

He never intended for it to escalate to something more, and if you asked him — Cosmos found himself ever so slightly scared of the alien twins presented before him. And yet, somehow, throughout his days with the pair, it softened into a more quiet, fuzzy hum.

Suspicious feelings turned into warm fuzziness that seemed to claw at him — haunting him with every second of his wake. 

Tossing in bed didn't help.

Sleeping didn't help.

And training? It definitely didn't help.

HRKK!

Cosmos winced as the tree before him came undone, falling to the ground with a large crackle that rang out throughout the place — he only hoped the action hadn't disturbed any wild life.

He was frustrated, yes. 

He never felt like this before.

Sure, Helpy used to be able to get his heart fluttering — but this? This was a whole other feeling threatening to consume him whole.

And like the idiot he was, Cosmos found himself giving in to the demand, rather than fighting back the void wrapping around his body and pulling him into territories he never thought he’d cross.

But that wasn't the worse of it.

At least with Helpy, there was a chance that they could love him back. A chance that they could have a happily ever after.

Gemini? Cosmos laughed at that thought — the idea of his feelings being mutual was like the concept of a pig flying in the air.

It couldn't happen.

So he did everything he could to erase the crush — not wanting it to bend the lines of their friendship, or worse, damage it. 

He gritted his teeth, tightening his grip upon the thin bark he had managed to rip away from the dying tree, ignoring the pricks grazing across his metal.

It. wouldn't. go. away.

He tried everything.

But apparently everything wasn’t enough, because all the universe did was laugh in his face — then proceed to spit down at his feet mockingly, leaving him with mixed feelings of resentment and hatred.

Sometimes he just wanted to bury himself into the ground — curl up and forget about everything that had happened.

But it was almost as if Gemini themself despised him. Because the moment he thought the crush was fading — they’d pop up with an intensity that somehow managed to get him to fall harder for them.

Every. Time.

Without fail.

Either they were playing willing mind games with him for the fun of it — a sadistic part of them Cosmos had failed to truly see.

Or, they were clueless.

Cosmos hoped it was the second option.

CRACK!

The already fallen tree split into two, the wood coming undone and flying apart under Cosmos’s wrath. His body began to tremble with the force he had to apply, a burning ache present in his wrist.

He shuddered, then took a step back.

What’s the meaning of this?” 

Cosmos whipped his head towards Gemini, taking a step back and opening and closing his mouth like a gaping fish — mentally cringing at the image that arose from that thought.

Goodness, he had to look extremely dumb currently.

“..Coosmoosss, it’s not time for training, what are you doing?” Pollux asked curiously.

Cosmos pressed his lips together, stabilising his body and shifting uncomfortably under their gaze, (Were they even looking at him? He couldn't tell. Goodness, somehow the absence of pupils managed to make them all the more attractive.)

“I—” Cosmos choked out, pressing a hand to his neck and blowing a raspberry awkwardly, “..Decided to train early?”

Gemini narrowed their eyes.

They saw through the lie.

Cosmos winced.

Odd.” Castor’s voice tinged with suspicion, dry and monotone —  though the intent was already clear. He expected  for Cosmos to tell the truth, and his words only served to be a warning.

Guilt hit him immediately — as if a truck ramming itself into him aggressively, and he found himself immediately spilling everything.

“Theres.. Emotions happening.” Cosmos tapped his foot against the ground to try and soothe the nerves currently attacking him aggressively.

“And I… needed to get it out?”

So you thought destroying things would be good?”

Cosmos crumbled.

..Maybe shooting down trees to get his mind off of Gemini wasn't exactly good — or a healthy coping mechanism.

Castor sighed, a hint of disappointment present in the way Gemini moved their body.

Their body intensified with a white, blinding colour — before they parted into two different forms. Almost immediately, Pollux took a step towards Cosmos, reaching a hand out to his cheek.

Cosmos found himself freezing in position as her (Rather terribly hot, but what did he expect? She was a star.) fingers brushed up against his cheek, wiping off the bits of oil remaining there.

She flicked the oil off of her hand with a quiet hum, blinking at the ground.

Since when did he start bleeding?

“Woah, I can hear your fans from here!” She giggled out loud, causing Cosmos to become increasingly aware of how hard his fans were whirring — working overtime as he accidentally overheated himself from pure emotions.

“Uhm, yeahhh.” Cosmos brushed a foot against the ground circle-motion to keep himself occupied, eyes lowered so he wouldn't have to face them directly.

He made the mistake of looking up — flinching at the sudden proximity between him and Pollux, the two almost touching each other.

He took a step backwards, flinching.

Pollux seemed to be observing him, her head tilting to get a better look at the entirety of his body — before she hummed and propped herself up, seemingly satisfied with her observation.

“Well.. Since we’re here, we might as well get training started!’ And with that, she clasped her hands together — moving onto her tippy toes and bouncing up and down and excitedly.

Cosmos bit back the dread building up.

 

Training went normal as always — or as normal as it could be. In the end, Cosmos had messed up so terribly, Castor had grabbed his waist and adjusted his position to show him how to properly do it.

And Cosmos, was most definitely, not flustered at all. His fans whirred even louder than before, drowning out majority of everything he heard, which unfortunately made it harder for him to hear Castor.

Cosmos only prayed that Castor did not see the trembling in his body as his hand brushed up against his waist. Prayed Castor didn't see the way he melted into it with a shudder.

Goodness, was he that touch starved?
It was rather pathetic, if you asked him. Being so touch starved to the point where the touch of an alien is enough to make you melt from the insides and out.

And worst of all, Cosmos could practically feel Pollux’s gaze burning into him, watching his every move — calculating, waiting, expecting. Like she knew something he didn't, like she expected something he didn't have the answer to.

He didn't even know how love worked for Astrals.

Cosmos bit his tongue.

He needed to stop obsessing over the idea of them being together — he had already abandoned the idea,  yes, but it still remained in his mind, as childish as it was.

“There.” Castor hummed in delight (Or was it delight? He could barely tell, but the idea of Castor being delighted with him made him shudder in delight. God, he was a freak.) as Cosmos managed to actually accurately sway the snow he summoned.

His head hurt.

Warning: Battery low.

Cosmos would scream into his hands if he could muster up the energy — and if he was alone. But he wasn't, and he had made the mistake of taking many sleepless nights the past week, meaning his battery was dangerously low.

“Heyyyy, Im talking to yooooou!” Pollux perked up into Cosmos’s vision, pushing herself extremely close to him and tilting her head at him, “Why are you ignoring me?”

Cosmos shook his head, fighting off the dizziness beginning to swarm in his vision.

“Uhm, my battery is really low.” Cosmos stepped back, rubbing the back of his head once more and sparing an awkward glance towards the two.

Pollux and Castor spared a look at each other.

“Oh, well, okay!! Go rest!” Pollux waved.

Cosmos didn't respond — he felt too tired to, simply choosing to speedwalk off.

Goodness, his head hurt.



Notes:

Feel free to comment! I quite love comments and they keep me motivated!!