The JL were having a normal, for them at least, meeting when suddenly a portal rips opens and spits out a young teen with snow white hair and glowing green eyes and he's carrying a bundle as he's stumbles out and lands on his knees in the meeting room.
The two main odd things about this kid was floating above the kid's head was a crown made of stars, ice, and the colors shifting like a aurora borealis and the bundle in his arms was strangely made of stars somehow, almost like a blanket of galaxies plucked out of the cosmos.
Before anyone of them could say or do anything, the kid turns around and screams towards the portal as he scrambles for it.
"JAZZ NO DON'T DO THIS! I CAN STILL FIGHT THEM! NONONONO!" but before he could reach the portal it snaps close.
The kid lands again onto the floor when he doesn't reach it in time, pleading for the damn thing to open again, and the bundle in his arms begins to cry from the jolting and noise.
The baby crying was the only thing that stopped the kid from pleading and instead focused his attention on the bundle in his arms.
"I'm sorry, I'm so damn sorry Ellie. I should had gotten us out of there sooner, I should had saved you bef- I'm sorry. I'm sorry for everything..."
Those were the rushed, raw words the kid said down to the bundle. The kid curled inwards a bit, to both shield the baby, who was calming down somewhat into tiny cry hiccups, and for himself.
Those with advanced hearing could tell the kid was still whispering apologizes under his breath as he held the baby close.
"I'm sorry everyone, I'm so sorry. I tried, I tried so hard to save everyone but in the end... I'm sorry- everyone's gone... I'm sorry."
Keep thinking back to the lines of Marie just roasting Agent 3 during splatoon 2's storymode- combined with playing an octoling in 3, I like to imagine the new captain left an unfortunate legacy behind
agent 18: so back to business, can I kill her (sunny) with your blessing?
slime: no, man! no, you can't fucking kill her! listen- come over here, come over here.
[...]
slime: listen, man. maybe if you asked me, maybe if you asked me an hour and 20 minutes ago. but something happened, okay? something happened, alright.
slime: i looked in her- in her sunny little eyes... i saw the universes in there. so no, you can't- you don't have my blessing to kill my fucking daughter, that's crazy.
slime: however you DO have my blessing to kill badboyhalo. you have my full blessing to kill badboyhalo.