Spar

As per Leon's request, Tony had spent the past two days in his lab, crafting something special for his brother. The result? A sleek, one meter long sword, its blade forged from a rare alloy Tony had developed with a blend of cutting-edge metallurgy and a trace of near mythical Adamantium alloy from Stark Industries, deepest vaults. It wasn't enough to make the whole blade indestructible, but it gave the edge a wicked sharpness and durability that could cleave through steel without dulling. Alongside the sword, Tony had designed a full body weight-bearing exosuit for Leon, perfect for training. "You asked for a weapon," Tony had said, tossing the sword to Leon with a cocky grin. "Don't say I never gave you anything."

....

Six days more flew by in a whirlwind of sweat and sparks. Pepper was a regular visitor to the villa. Leon threw himself into mastering his new weapon, swinging the blade in the reinforced gym until the air hummed with each strike, the weight-bearing exosuit pushing his limits. Meanwhile, Tony, the genius that he was, hadn't rested for days. Holed up in his lab with the support of Jarvis and top tier materials he created his first armor. The new suit was a masterpiece: stronger materials, smarter design, and a hell of a lot more firepower. Naturally, he painted it in his signature red and gold theme. "It's not just armor," Tony bragged to Jarvis. "It's a statement."

....

Confident his creation was ready, Tony decided it was time for a real test. He strode into the gym in his suit catching Leon doing one arm handstand push ups. "Hey, tough guy!" Tony's voice boomed through the helmet's speakers. "Ready to see what a billion dollars and a big brain can do?" Before Leon could answer, Tony raised his right hand, and a repulsor blast struck out, a streak of white-hot energy aimed straight at his brother.

Leon rolled aside, the blast scorching the floor. "A little warning, maybe?" he grunted, springing up, sword in hand.

Tony's laugh crackled through the speakers. "Where's the fun in that? I am helping you refine your senses." He clenched his left fist, and a salvo of micro-missiles erupted from his gauntlet, streaking toward Leon like angry hornets.

Leon moved like a shadow, weaving through the barrage with the grace of a predator. Training with weight-bearing armor made him faster and stronger than before. Tony upped the game, unleashing a hail of bullets from his shoulder mounted guns. Leon's sword flashed, deflecting a stray round with a sharp *clang* "Not bad," Tony admitted, "but let's kick it up a notch. Jarvis, targeting assist, now."

"Yes, sir," Jarvis replied. Inside Tony's HUD, red crosshairs locked onto Leon's every move. The next wave of bullets was relentless, guided with surgical precision. Leon twisted and dodged, but the sheer volume was overwhelming, grazing his arm. With a growl, he charged. "My turn!" he roared, swinging the blade two-handed. 

Tony's thrusters flared, rocketing him back, but Leon's follow up slash caught his side. Metal screeched as Tony crashed to the reinforced wall, armor dented but holding. He yanked off his helmet, wincing. "Hey-Hey man I give up! Your sword is darn too heavy, it feels like a small car hit me"

Leon smirked, lowering the sword. "Your armor held up, barely. It needs more work." He offered a hand, pulling Tony up.

Tony rubbed his side, eyeing the dent. "Yeah, I'll tweak it. With practice, I'd smoke you from the sky."

Leon nodded. "High altitude's my weak spot, sure." 

'But not for too long.'

After a brief pause, Leon turned to him. "Tony, have you tested high altitude flight yet?"

Tony shook his head in puzzlement. "Not yet. Why?"

 "You fitted it with anti-icing?"

Tony's grin faltered. "Damn it, icing. It completely slipped out of my mind."

"And Tony," Leon added "your suit's weapons could use some work. They're strong, but they're not hitting their full potential."

Tony glanced at Leon, his brow furrowing. "Yeah, I've been thinking the same thing. Problem is, I can't. The Ark reactor's got juice, but it's not infinite." He shook his head. "Palladium's got limits, man."

Leon's lips twitched into a faint smirk. "If that's the bottleneck, I've got a fix. Check Dad's old model in his office. He was obsessed with energy breakthroughs, palladium was a stopgap, not his endgame. Maybe you will find something in it that can help."

Tony froze, his head snapping up to pin Leon with a stare. "Wait, hold up. A solution? In that dusty old relic?" His voice danced between disbelief and intrigue, the gears visibly spinning behind his eyes. "Why do you think that?"

Leon shrugged, leaning back with a knowing glint. "Call it a hunch. Dad was always ten steps ahead, right? I figured he'd stash something big in there related to the Arc reactor."

Tony muttered, "If you're right, I owe Dad a toast and a punch for keeping secrets." He straightened. " But first I'll fix the icing issue. In the meantime, can you swing by the company and bring the model?"

"Alright." Leon nodded.