2014 - The 3rd Eruption occurs.
2016 - The Honkai is officially eradicated.
2019 - Kevin and Bronya are married.
2020 - Bronie is born.
2025 - Events of "The Madam is an Ex-Valkyrie."
2036 - Bronie and Welt Yang encounter the Astral Express and its owner, Himeko.
2037 - Current timeline of Honkai: Star Rail.
The Astral Express.
A train capable of freely traversing the boundaries between countless worlds.
In reality, while it possessed the silhouette and designation of a locomotive, it was effectively a colossal, interstellar spacecraft.
"Ugh..."
Having lost a game of rock-paper-scissors, the young girl—Bronie—had been relegated to guarding the train instead of exploring Herta Space Station. Suddenly, a strange sensation prickled her skin, and she looked out the window.
"What is it, Bronie?"
Seeing his fellow Trailblazer's reaction, Welt Yang—who had traveled from the same homeworld as her—lowered his newspaper and looked toward her.
"Nothing specific. I just have a bad feeling about this."
Welt's brow furrowed. He folded his newspaper neatly. If anyone else had said that, he might have only paid it half a mind, but this was Bronie.
Her father possessed an instinct so sharp it was practically a superpower—an 'Ultra Instinct.' Bronie had inherited that exact trait from him. In a situation like this, her intuition was impossible to ignore.
After all, that gut feeling had saved them several times before.
"Hm? A bad feeling, you say?"
The voice belonged to someone who had been listening to their conversation.
A rabbit-like entity with short limbs and ears nearly as tall as its own body approached them. Wearing a large, ornate conductor's hat and a long coat that draped over its form, this was Pom-Pom.
The mascot of the Astral Express and its dedicated Conductor.
"It's exactly what it sounds like. Someone has entered the space station. And they didn't follow protocol like we did—they bypassed the defensive barriers artificially."
"R-Really?" Pom-Pom stammered.
"Yes, Conductor. Hmm... tracking their Ki signatures, I'd say two individuals just broke in."
"Isn't that a huge problem?!"
"...Yes. And it looks like the fallout is already starting."
Bronie looked out the train window again. As Welt and Pom-Pom followed her gaze, they saw people screaming, fleeing in terror from something in the distance.
Ebony creatures with arms shaped like jagged blades were manifesting.
It was questionable if they could even be called biological organisms, but everyone aboard the train recognized the threat immediately.
"The Antimatter Legion?!"
"We need to hurry," Welt stated firmly.
"No, it's fine."
Bronie stepped in front of the rushing Welt, a smirk playing on her lips. Seeing that expression—the look of someone who had just found a source of entertainment—both Pom-Pom and Welt relaxed, letting out sighs of relief.
While she bore a striking resemblance to Welt's former pupil, the current CEO of Anti-Entropy, her personality was a carbon copy of her father's. Specifically, that belligerent streak where a smile would creep onto her face the moment a fight was about to break out.
"I'll be back in a bit!"
"...Fine."
"Make sure to meet up with Himeko and the others while you're at it."
"Got it~!"
With those words, Bronie pulled a pair of gloves from her pocket and slipped them on.
"Now then, shall we get started?"
Bronie watched the fleeing crowd and pressed her index and middle fingers to her forehead. In a flash of afterimages, she vanished.
Seeing her go, Welt tapped his cane lightly against the floor of the Express. Honkai Energy surged from the tip of the cane, rippling outward until it coated the entire train before turning invisible.
It wasn't gone; he had simply shielded the vessel. It was a specialized coating of gravity manipulation, ensuring the Astral Express could withstand almost any incoming assault.
Meanwhile, where had the vanished Bronie gone?
"Aaaaagh!"
A researcher from Herta Space Station squeezed his eyes shut as a Voidranger: Reaver swung its blade toward him. He waited for the agony of the killing blow, trembling in fear, but as several seconds passed without pain, he gingerly opened his eyes.
His jaw dropped.
"Ah, you're finally awake?"
A teenage girl was standing right there, blocking the Voidranger's blade with a single index finger.
"Have you seen a beautiful lady with red hair and orange eyes? She'd be with a stoic guy with black hair and green eyes, and a girl with pink hair and blue eyes who's so energetic it's practically exhausting."
"I... no, I haven't..."
"Really? Well, I didn't expect to find them so easily in a place this big."
Bronie shrugged. In that same instant, the Voidranger's entire body cracked. With a soft crumbling sound, the creature disintegrated into fine dust.
The researcher's eyes went wide at the impossible phenomenon.
"Wh-What was that?"
"Oh, this? It's simple. I used resonance."
"Resonance?"
"Yeah. While maintaining contact with the target, I feel out their natural frequency. Then, I use my Ki to match it. Ta-da~ and they just fall apart like that."
—By the way, good children shouldn't use this on people. Good adults, too!
Maintaining her strangely upbeat tone, Bronie gave the dazed researcher a cheerful wink.
"Now that your curiosity is satisfied, hurry to the shelter. I've got people to find. Catch ya later!"
As Bronie disappeared as quickly as she had arrived, the researcher stared at the pile of dust that used to be a Voidranger and muttered to himself.
"What the hell was that...? That's terrifying."
Name: Bronie S. Zaychik
Gender: Female
Age: 17
Description: A passenger on the Astral Express hailing from the same world as Welt Yang. They share a grandfather-granddaughter-like relationship.
She has inherited the potent 'Super Saiyan' bloodline of her father, granting her the ability to transform. She also wields the power of her mother, the Herrscher of Truth, allowing her to manifest various weapons at will.
However, she rarely creates weapons for herself, claiming she prefers the 'tactile feel' of close combat. She only uses her manifest powers to sweep away weak 'mobs.'
Having experienced a sudden growth spurt in the last year, she frequently changes outfits—a fact that Himeko and March 7th have gleefully exploited, turning her into their personal dress-up doll, much to her chagrin.