Originally from this prompt.

Back in the seventies, the Mechanist had been a real terror. Creating power armour, taking over planes and cars, even inventing the concept of robot armies, which so many had copied since. Oh, he still got respect from the new tech supervillains, the hackers, cyberghosts, and AIs, who sometimes popped into his lair to say hi, get autographs, and meet the legend. And just last week, when Cyberflame had dedicated her hack of the New York Stock Exchange to "the Mechanist, the first super hacker", he'd felt a twinge of nostalgic pride.

But times had changed, and machines with them. Gone were the punch card readers and dedicated word processors of his prime, replaced by the internet and cyberspace. He was basically retired nowadays. He spent his hours writing for robotics journals under a dozen aliases, informally mentoring the new generation of supervillains about the hands-on aspects of supervillainy, and keeping an eye on his equally-retired rival Gaia's Knight. She'd been a nasty one to deal with; once her vines got into the cracks and seams of his machines, and fungus gummed up the gears and old-style transistors, his robot army had fallen apart pretty quickly. The Mechanist smiled fondly; that had been a battle for the history books.

He was shaken from his reverie by an AI pinging his lair.

"What is it, Athena?"

The AI's computer-generated face appeared on a screen.

"News of your rival. The press figured out her secret identity." The AI, one of Cyberflame's rogues, grinned, showing just a hint of the uncanny valley. "I was going to go get her, but it seemed disrespectful not giving you the first shot at it."

The Mechanist leaned back in his chair and rubbed his eyes wearily.

"Can you keep a secret, Athena?"

"Of course," she said indignantly, "I'm already encrypting this conversation." He sighed. Computers were still literal after all this time.

"Will you keep a secret if I tell you one?"

"Yes, for you. I still owe you for that lair you set me up in." The Mechanist waved her thanks away.

"I've known Gaia's Knight's identity for years."

The AI froze, and the image flickered in and out.

"Wha- How- You hate her!"

"I used to," he replied, "back in our twenties, we were trying to kill each other every other week. But after a while, it became routine. Normal. And by the end of my career, we were mostly trying to capture each other instead, for the prestige." He shrugged. "And now she's retired, and mostly spends her time doting on her grandkids."

He leaned back and stared at the ceiling. "Back in my day, we didn't reveal identities, not even your rival's, at least not to the press. Other supers sometimes, if they needed an edge, but never publicly. She knows mine too, you know? One of two people alive who do. Figured it out when she caught me one time."

The AI was still flickering erratically when he looked back at her. "Actually, Athena, I don't think I'll let this stand. And you're going to pay me back for that lair with a little video editing."

He entered his mech suit for the first time in five years, admiring the interface upgrades a fan had made for him. He bundled himself, the mech, and a few dozen robot inside an anonymous semi trailer, and drove to Carol's suburban home. The press had the house surrounded; they'd been big names on the international stage in their prime, and were still newsworthy today. He grinned, feeling adrenaline pumping again. Time to give them an entrance to remember.

The sides of the trailer crashed to the ground, his robots flew and crawled out in a deafening clatter of metal on concrete and whirring rotors, and his mech unfolded to its full twelve-foot height.

"Gaia's Knight," he roared over the speakers, "I've found you!" His robots went straight for the trees, which fought back, and not-incidentally caused the press to scatter. A few smoke bombs later, and he was sure no one could see the fight except through his broadcast, which Athena was running. He hopped down from the mech and knocked on the door. Carol answered it with a sword in her other hand.

"Justin?"

"I'm here in peace," he assured her rapidly. "I'm streaming video of myself fighting Gaia's Knight, with you trying to get out of the way, and very obviously not a hero."

"But... why?"

"Nostalgia? Honour? I'm not sure myself," he admitted. "Seemed to me like a sad fate for one the old guard." She nodded. They stood awkwardly in the doorway for a while, and he turned to leave.

"Thank you," she said.

"Thanks enough for you to return that power core you seized last time?" He said hopefully, looking back.

She slammed the door in his face.

He shrugged, it had been worth a shot. He reached out his hand, and the robot which had snuck in while they were talking handed him her magical amulet. He'd have to set up a trade later. He whistled as he got back into his mech. Just like old times.