Ben 10:Ultimate Marvel

Ben sat at the small fold-out table inside the Rustbucket, hunched over a mess of scattered blueprints and notebooks. In his Gray Matter form, everything flowed easier. Ideas that would've taken hours as a human now took minutes. His tiny three-fingered hand scribbled equations and sketches like he was on autopilot.

The quiet hum of the Rustbucket's engine served as soft background noise while he worked on refining plans for upgrading their ride—not flashy stuff, just basic optimizations: better suspension, reliable brakes, and a new internal power source. No sleek sci-fi spaceship look on the outside. He wanted it to still look like an old RV, just run like a dream inside.

"Hey, genius," Gwen's voice pulled him from his trance.

Ben flinched slightly. He'd been so deep in thought he hadn't noticed her step in. He looked up at her from the edge of the table, her silhouette framed by the Rustbucket's doorway.

"Oh. Uh, hey," he said, voice higher and squeakier in his alien form.

She stepped closer and peered down at the notes. "Still geeking out, huh?"

"It's not geeking out. It's... preemptive mechanical failure prevention," he said, trying to sound cooler than he looked—while sitting in a hoodie with a foot-tall alien brain.

She chuckled and sat down across from him. "Sure, Ben. So, what's next? You gonna turn the Rustbucket into a spaceship?"

He looked at her, genuinely caught off guard by the smile she gave him. And for a second, he didn't have a comeback. Then her fingers reached for his papers, flipping through the designs.

"You think this stuff would work?" she asked, sounding curious.

"Yeah," Ben nodded after turning back into his human form . "It's mostly just tuning up what's already here. Grandpa's RV is so old and ruty. I don't want to mess with it too much until I know what I can do with it plus grandpa love the RV ."

Gwen leaned back slightly, glancing at her small bunk bed against the side of the RV. "Hey… uh, while you're doing all that... think you could maybe make my bed a little bigger?"

Ben looked at her. His immediate instinct was to say "no"—but the way she tilted her head, smiling just a bit, with those wide eyes?

Damn it.

He rubbed his face. "Sure," he sighed. "Four inches max. It'll fit. But only because you asked nicely."

Gwen smiled. "Aw, I knew you were a softie."

Ben groaned internally. "I hate that I can't say no to you."

He turned away, cheeks burning from look at her. "I'm starting to hate teen hormones more than anything else."

Ben went back to his notes with lingering weirdness of his smarts. He stood, stretched his arms, and turned to Gwen. "Come on, let's get to work. Might as well get this over with before Grandpa gets back."

Together, they stepped outside. The sky was partly cloudy, soft light leaking through, and the wind carried a dry warmth. Ben led her a little ways behind the RV to where he'd buried the robot from the last incident. The dirt was still slightly disturbed from before, and with Upgrade's help, it didn't take long to unearth the bot again.

Ben handed Gwen the small notebook full of diagrams and notes from earlier.

"This is what I'll be using to upgrade the Rustbucket," he explained. "Nothing major—just a better power source, smoother suspension, new brake system, and a little size adjustment for your bed."

Gwen flipped through the pages slowly, eyes scanning the details. "This is… actually really solid work. Like, college-level engineering."

Ben scratched his head. "Yeah, well… Galvan brains are kinda insane."

She glanced up at him with a smirk. "And here I thought you were just watching cartoons in that tiny alien head."

"I do both," he shot back, then hesitated. "Also… maybe I enjoy impressing you a little."

Gwen blinked at him, caught off guard. "What?"

Ben's face turned red instantly. "N-Nothing! Forget I said anything!"

She stared at him for a moment longer, then looked back down at the notes, flipping another page with a small smile. "Well… thanks for the bed thing."

Ben turned around before he had to say anything else stupid. The black liquid metal form absorbed into the Rustbucket's exterior, spreading like oil and vanishing beneath the surface.

Inside, he got to work. Circuits lit up in his mind. He replaced frayed wires, upgraded the brakes, patched old pipes, rerouted the power system to run off a compact hybrid unit he crafted from scrap. It wasn't flashy, just efficient—something Grandpa would appreciate without asking questions.

He added a few centimeters of space to Gwen's bed, just enough for comfort, then carefully reinforced the support beneath it. He even adjusted the angle of her reading light to be softer on the eyes. It was the kind of thoughtful detail he'd never admit out loud.

As he moved deeper into the internal tech, he stumbled across more advanced systems hidden behind panels—encrypted tracking relays, Goddame Jets to fly even , even low-profile energy scanners. Nothing active, just dormant.

Upgrade paused.

Grandpa Max really is something else huh, he thought.

He made a mental note of it but didn't touch a thing. No matter how curious he was, this was Grandpa's stuff. he wasn't going to mess with it—at least, not yet.

He slid out of the RV, liquid form peeling off and reforming into his human self in front of Gwen.

"All done," he said, dusting off his hands.

"Already?" she asked, looking impressed. "That was fast."

"Upgrade's basically a cheat code," he said, grinning.

Gwen opened the door and peeked inside. Her eyes lit up. "Ben… this is amazing. You upgraded it like it's brand new vehicle under the same shell."

He shrugged like it was no big deal, but he couldn't hide the grin tugging at the corner of his mouth. "Just a tune-up. Figured we might need it."

Before Gwen could say more, her phone buzzed. She stepped aside to check it.

Ben looked up at the sky, watching clouds roll across the horizon. The moment was calm.

Meanwhile, in another state…

Inside a dusty RV parked behind an abandoned truck stop, Dr. Alimno leaned over a cluttered table. Glass vials, glowing samples, and a caged bullfrog sat nearby. The frog croaked nervously.

Alimno cackled to himself, wiping sweat from his brow as he lifted a syringe filled with glowing green fluid.

"They said I was insane," he muttered. "Told me to bow to their rules. Work under their labs. I won't be their pawn—not the X Foundation, not anyone."

He jabbed the needle into the frog and watched as the animal spasmed violently. Its body convulsed, shifting and warping unnaturally. After a long, tense moment, it stilled—bigger, bulkier, and covered in strange scales.

Alimno grinned. "Progress."

He turned toward the wall, where papers were tacked up—maps, mugshots, scattered X-markings. One was labeled in bold marker: Mutant Pursuer?

"Let them come," he whispered. "They won't stop me. I'll perfect this world one gene at a time....