No Need for a Flashy Entrance

From the moment Yinsen learned the current point in this universe's timeline, he knew the "plot" of this world had already reached a stage familiar to him.

Superman had already grown into an adult. Confused by how different he was from everyone else, Superman had learned from his adoptive parents that he was not from Earth. Following his adoptive father's advice, he had decided to hide his powers and live as an ordinary person.

Not long afterward, his adoptive father died in an accident. Superman, now known as Clark Kent, fell into confusion and began wandering everywhere, helping people in need along the way.

Once he found the "inheritance" his biological father had left him—the ancient Kryptonian scout ship—this world's Superman would officially be born.

That would not have been a major issue, except not long after Superman's "birth," another group of Kryptonians arrived on Earth.

Led by General Zod, these Kryptonians were determined to rebuild their homeland—or rather, create a new Krypton.

To rebuild Krypton, they needed not only a suitable planet but also its people. In the final moment before Krypton's destruction, Superman's father had sent his son away and also sent away Krypton's central Codex.

General Zod needed to recover the Codex if he wanted to rebuild Krypton.

The Kryptonians had already abandoned traditional reproduction, choosing instead to "cultivate" the people they needed. Even their talents were predetermined from the start. From the day they were born, everyone grew in the "correct" direction and took up the work assigned to them long ago once they reached adulthood.

The central Codex that Superman's father had sent to Earth recorded every type of Kryptonian gene.

For that very reason, the Codex was something General Zod had to obtain, though at first he did not know that the so-called Codex