Mark threw himself into training with an intensity that surprised even him. He couldn't exactly tell his father why he was so driven—Nolan would have been suspicious—but he used every opportunity to build himself up. His school gym became his sanctuary, and he signed up for martial arts classes under the guise of wanting to get ready for when his powers awaken.
By the time he was 14, Mark had developed a solid foundation in multiple fighting styles. Boxing taught him precision and endurance; jiu-jitsu gave him control and grappling techniques; muay thai made his strikes devastating. With his Viltrumite powers not awakening yet, Mark relied on his wit and willpower, pushing his limits every single day.
Late at night, when the house was quiet, Mark would practice in secret. He shadowboxed in his room, replaying techniques in his mind over and over again. He studied online footage of fighters and heroes alike, analyzing their moves, imagining how they'd fare against someone as strong as a Viltrumite.
The years passed, and Mark's anticipation only grew. He waited for the day when he'd finally feel the strength of his Viltrumite blood coursing through his veins. Some days, he'd catch himself staring at his reflection, wondering what it would feel like to fly, to punch through solid steel, to be invincible. He knew he would have to wait until he was at least 17 due to being a late bloomer like in the comics, but he was still excited.
While Mark diligently trained for the challenges he knew lay ahead, he also made a conscious effort to embrace the life experiences he had missed in his past life. He joined his middle school basketball team, made some friends, got his driver's license, and even took tentative steps into the world of dating, all to live a fuller, more balanced life.
It happened a few months after his 17th birthday. Mark was taking out the trash at Burger Mart after a long shift. He had taken the job so he could know when his powers would come in just like in the series. When Mark started lifting the trash to throw it in the dumpster, it suddenly flew off into the atmosphere.
"...YES!!" Mark exclaimed as he started dancing around. His powers really did come in just like in the series and he was ecstatic.
But just as the euphoria set in, a wave of physical and mental pain hit him. Mark could feel his muscles tightening providing strength he wasn't expecting even with his Viltrumite heritage. His senses sharpened—he could hear the hum of a streetlight blocks away, and smell the grease from the restaurant's fryer even through the night air. His mind exploded with images. Crystalline towers rising under a red sun. Symbols and words in a language he'd never learned but now understood perfectly. Memories of a world called Krypton, of its history, its people, and its final days.
Mark stumbled backward, his head spinning from his heightened senses. The Codex provided him with the memory of how it had fallen into the teleporter, fused with his fading soul in the void, and was the reason he was brought to the Invincible Universe. The codex was inactive for 17 years, until Mark's Viltrumite genetics awoke, allowing the codex to assimilate Kryptonian DNA with his Viltrumite DNA.
Remembering the Superman comics he had read during long hours in his hospital bed in his past life, Mark focused on gaining control over his newly awakened senses. Fortunately, his Kryptonian powers, while impressive, hadn't yet grown too overwhelming to manage. After an hour of concentrated effort to quiet the barrage of sounds flooding his ears, he succeeded in dialing back his hearing to the level of a slightly above-average human, giving him a small but meaningful victory.
"Woah, that was way harder than the movies and comics made it look," Mark muttered to himself. He walked back into Burger Mart, ripped off his apron, and marched up to his manager, shoving it into their hands. "I quit," he declared and walked out of the store.
Mark wanted to get a handle on his powers before heading home, so he made his way to the nearest park. 'The Codex and my Viltrumite genes seem to be helping me adapt to my powers quickly', he thought, a mix of excitement and determination bubbling within him. 'But let's put them to a real test'.
Scanning the park, he spotted a secluded area surrounded by trees, offering enough cover to avoid being seen. Once there, he took a deep breath, kneeling down to center himself before attempting his first real flight.
The sensation was strange at first, like his body was learning to balance two distinct methods of flying. His Viltrumite side provided him with natural biological instincts, almost as if he'd always known how to propel himself through the air in any direction with sheer willpower. At the same time, his Kryptonian side activated a bioelectric field, allowing him to negate gravity's pull and move with effortless precision.
The dual sensations felt alien yet harmonious as if both sides of his heritage were working together. Mark couldn't help but grin as he pushed off the ground, ready to see just how far his newfound powers could take him.
.
.
.
Notes:
I've drawn inspiration from Man of Steel's version of the Codex, but I'll be incorporating my own ideas as well. As a result, it might not function exactly as it does in the movie. Also, while my character has read the comics, things may follow the storyline of the show until a certain point.