The Magus In Marvel

The sound of ocean waves crashing against the cliffs of Malibu was a stark contrast to the chaos of battle and the grandeur of Asgard's victory banquet. Tony Stark's sleek, AI-operated private jet touched down on the landing pad beside his sprawling mansion, the soft hum of repulsor technology fading as the aircraft powered down.

The doors hissed open, revealing two utterly exhausted figures. Tony stepped out first, his Iron Man suit having long since retracted into its compact form, leaving him in his now slightly tattered undersuit. Behind him, Rin wobbled slightly on her feet, her deep blue cloak still dusted with remnants of Svartalfheim's ashen soil. She rubbed her eyes, the fatigue settling deep in her bones.

"Never thought I'd say this, but I think I'd take a high-stakes board meeting over another round of mead toasts," Tony groaned as he ran a hand through his disheveled hair. "Asgardians sure know how to throw a party, but someone needs to teach them about pacing."

Rin, who had been unusually quiet, simply hummed in response, her steps sluggish as she followed Tony into the house. It wasn't just the banquet that had drained her—though the endless toasts, songs, and exaggerated retellings of their battle had certainly taken their toll. The battle itself had demanded everything from her, both physically and magically. Her reserves were nearly depleted, and even standing upright felt like a monumental effort.

J.A.R.V.I.S. greeted them as they entered. "Welcome home, sir. I trust Asgard's festivities were to your liking?"

"Define 'liking,' J," Tony muttered, heading straight for the bar before thinking better of it and redirecting himself toward the nearest couch. He flopped down unceremoniously, arms spread. "We survived, got a hero's welcome, and now I think I've earned at least twelve hours of uninterrupted sleep."

Rin, on the other hand, forced herself to stay upright, despite the overwhelming urge to collapse. There was something she had meant to ask. Something important. She squinted at Tony, the thoughts bouncing around in her head like marbles in a tin can.

"You—" she started, pointing at him with a slightly wobbly finger. "Your armor."

Tony cracked one eye open. "Yes, I know, it's amazing. Revolutionary. Borderline magical. Oh wait—literally magical now. Thanks for noticing."

Rin frowned, determined to argue, but her tiny ten-year-old frame betrayed her. Her limbs felt like lead, her thoughts sluggish. She tried again. "You... used mana. You... don't have circuits."

Tony sat up slightly, watching her with mild amusement. "Oh, you mean that little upgrade? Yeah, turns out, hanging around gods and mages kind of rubs off on you. Figured I'd experiment. Results were pretty awesome, if I do say so myself."

Rin gritted her teeth, her mind screaming at her to demand details, to grill him on how he'd managed such a feat, but her body had other plans. She wobbled again, and before she could launch into a full-fledged interrogation, her legs gave out.

With an exasperated sigh, Tony caught her before she hit the floor, easily scooping her up. "Okay, okay. I get it. The grilling session can wait."

Her half-lidded eyes managed a feeble glare. "Not... getting out of it... Stark..."

He smirked. "Wouldn't dream of it, kid."

J.A.R.V.I.S. chimed in. "Shall I prepare a guest room for Miss Tohsaka?"

Tony glanced down at the now fully unconscious girl in his arms and sighed. "Yeah, J. Make sure it's extra comfy. She's got a storm brewing in that tiny head of hers, and I have a feeling I'm about to be on the receiving end of it when she wakes up."

With that, he carried her inside, the sounds of the ocean a steady backdrop to their much-needed return to normalcy—at least, for now.

The next morning, the peaceful quiet of Malibu was shattered by the determined stomp of tiny feet. Rin had woken up well-rested, and unlike last night, when exhaustion had stolen her opportunity, she was now ready to hound Stark for answers.

Marching into the kitchen, she found Tony casually sipping coffee, his feet propped up on the table as he read through holographic schematics. He glanced up as she approached, already smirking. "Let me guess—grilling session starts now?"

Rin crossed her arms. "You agreed not to run any tests on me, Stark."

Tony held up a hand in mock surrender. "And I didn't. No needles, no scans, no freaky sci-fi experiments." He took another sip of coffee before adding, "I just did what any genius would do—observe."

Rin's brow twitched. "Observe?"

Tony tapped his temple. "Magic—magecraft, whatever—still follows one fundamental rule. You need energy to make things happen. And energy? That's my specialty. I didn't need to poke at you to figure out how it works; I just tuned my sensors to different frequencies and wavelengths whenever you or anyone else used magic. Data was right there, just needed the right instruments to read it."

Rin narrowed her eyes. "And?"

"And turns out," Tony continued, setting his coffee down, "mana is an incredibly versatile energy field, but it isn't limitless. It follows principles not unlike electromagnetism—flow, resonance, and conversion efficiency. Some individuals—like you—can act as natural conduits or generators. I haven't figured out whether that's purely genetic, environmental, or artificial, but the point is, once I identified the energy pattern mana follows, I reconfigured my armor to resonate with it. Like tuning into a radio station."

Rin clicked her tongue, visibly impressed despite herself. "That… makes an annoying amount of sense."

Tony chuckled. "That's science, kid. Annoyingly making sense since forever."

But as he spoke, a thought lingered in his mind—one he chose not to share. Even with all his adjustments, replicating magical feats shouldn't have been this easy. Not unless…

The frequency of mana was eerily similar to the one he got from his arc reactor.

Tony hesitated for the briefest moment before taking another sip of coffee, pushing the thought aside for now. He wasn't sure what it meant, but it raised more questions than answers.

Meanwhile, Rin's mind was still whirling with the implications of what Tony had told her. Before she could push further, he clapped his hands together. "Anyway! That's enough magic talk for now. I need another cup of coffee, and you probably need breakfast. J.A.R.V.I.S., how about some pancakes?"

The AI responded smoothly. "Of course, sir. Preparing now."

Rin huffed but let it go—for now. There would be plenty of time to interrogate Stark later. For now, pancakes.