The workshop's air crackled with tension thicker than Tony's fifth espresso. Leon hovered cross-legged above a floating workbench, surrounded by holograms that twisted like quantum origami. Across the room, Tony's latest armor prototype gleamed with the desperate shine of a man clinging to his last shred of superiority.
"Final adjustments," Tony muttered, slapping a panel closed with more force than necessary. The Mark II's HUD flickered to life, projecting targeting reticles that danced across Leon's annoyingly serene face.
Leon didn't glance up from his own creation - a sleek silver exoskeleton that seemed to drink in the morning light. "Still using liquid coolant? How... 2010."
Tony's eye twitched. "It's called redundancy, you walking solar panel. Not all of us can sweat liquid nitrogen."
"Redundancy?" Leon's fingers danced through a holographic periodic table, atoms rearranging at his touch. "More like insecurity. Watch."
The silver suit's chestplate irised open, revealing a reactor core pulsing with captured sunlight. "Photonic plasma circulation. Self-sustaining, self-cooling, and..." He tossed a wrench at it. The tool vaporized in a corona of golden light. "...self-defending."
Tony's coffee cup slipped from numb fingers. "That's... that's..."
"Elegant?" Leon caught the falling mug with a flick of bioelectricity. "I know."
The workshop doors hissed open. Pepper stood framed in sunlight, her power suit immaculate despite the 3 AM timestamp on her StarkPhone. "Gentlemen." Her voice could frost vibranium. "Care to explain why R&D's entire titanium supply is..."
Her words died as twin armors hummed to life - one roaring with arc reactor fury, the other singing a solar hymn.
"...gone."
Tony and Leon exchanged glances, the unspoken challenge hanging between them like a fusion core criticality warning.
"Race you to the stratosphere?" Leon's grin mirrored the sunrise.
"Prepare to eat ionized particles, Sunboy." Tony's faceplate slammed shut.
As twin shockwaves shattered the mansion's windows, Pepper's scream joined the chorus of car alarms below. Somewhere in the chaos, JARVIS began drafting two very expensive insurance claims.