From the plot synopsis;
Thirty years ago, Jor-El and Lara Lor-Van sent their infant son Kal-El to Earth to escape the destruction of their home planet, Krypton. Raised as Clark Kent by adoptive human parents Jonathan and Martha Kent in Smallville, Kansas, the Kryptonian gains incredible powers from the Sun. Inspired to heroism by Jor-El and Lara's farewell message, which was damaged on the journey, Clark debuted as Superman, the most powerful metahuman on Earth, three years ago. He maintains a job as a reporter for the Daily Planet in Metropolis, where he works alongside Jimmy Olsen and Lois Lane, the latter of whom is in a relationship with Clark and aware of his secret identity.
Three weeks earlier, Superman had stopped an invasion by Boravia, an ally of the United States, of the neighboring country of Jarhanpur. Billionaire Lex Luthor assures General Rick Flag Sr. and others in the U.S. government—who wonder if Superman might be a threat—that he can kill Superman if necessary. Superman loses his first fight against the mysterious "Hammer of Boravia", who in reality is Ultraman in disguise, citing Superman's involvement in the war as the reason for his actions. However, unbeknownst to the world, Ultraman works for Luthor, who controls him using drones. Krypto takes an injured Superman back to the Fortress of Solitude in Antarctica, where he is healed with concentrated solar radiation. Luthor later secretly invades the fortress alongside Ultraman and the Engineer, steals the farewell message from Jor-El and Lara and decodes it in its entirety, before abducting Krypto.
As Superman and the Justice Gang—a team of heroes composed of Green Lantern, Mister Terrific, and Hawkgirl—battle a kaiju created by Luthor as a diversion, Luthor broadcasts the entire Kryptonian message to the world. To Superman's shock, in the second half of the message, his parents urge him to conquer Earth and take as many wives as needed to restore the Kryptonian race. Public opinion turns against Superman, and he voluntarily surrenders to the government for questioning; because of Superman's power, Flag gives custody of the hero to Luthor.
