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You had one mission and you veered from it because you are weak. You shall not veer from it any longer. Now go and complete what you were sent here to do. Become the Eradicator, or know that you are the sole reason Krypton was lost.
~ Zeta-Rho's consciousness within his son's mind, ordering him to become the Eradicator.
Zeta-Rho is the overarching antagonist of Season 1 of the TV series Superman & Lois. He was an ambitious Kryptonian, the father of Tal-Rho and the ex-husband of Lara Lor-Van who sought to use her invention, the Eradicator, to colonize other worlds by supplanting his people's consciousnesses into the inhabitants.
At some point in his life, Zeta-Rho was once married to Lara Lor-Van through genetic matching, and the two had a son together named Tal-Rho. Eventually, Lara left him after meeting and falling in love with Jor-El, angering Zeta-Rho deeply.
Upon learning about Lara's invention known as the Eradicator, which could be used to preserve Kryptonian consciousnesses after their deaths, Zeta-Rho developed ambitions to use it to spread Kryptonian influence. Through this means, he intended to upload Kryptonians' consciousnesses into inhabitants of other worlds which he could colonize and enslave. However, his plans never came to fruition with the destruction of Krypton.
Before Krypton's destruction, he sent Tal-Rho to Earth and left in his pod a crystal uploaded with his consciousness so he could colonize the planet. Out of spite for leaving him, Zeta-Rho stole Lara's crystal and stopped her from leaving it for her son Kal-El in his pod. When Krypton was eventually destroyed, Zeta-Rho perished with it.
Zeta-Rho's plans and ambitions were later adapted by his son, Tal-Rho. Tal-Rho's mistreatment by the British people fuelled his hatred and he sought to continue his father's plans and adapted the Eradicator technology to be used against humans. Tal-Rho was able to implant Kryptonian consciousnesses into humans using X-Kryptonite and sought to use it to make a new world of Kryptonians.
It was Zeta-Rho, who sought to colonize other worlds, and enslave their inhabitants as hosts.
~ Jor-El's A.I. recounting Zeta-Rho's ambitions to Clark.
Zeta-Rho was described as an ambitious individual who believed in Kryptonian superiority and sought to colonize other worlds to be enslaved in order to preserve Kryptonian consciousnesses into others. This differed from the majority of Kryptonians who were described as peaceful people by Lara.
Zeta-Rho was also shown to be an abusive and arrogant Social Darwinist who believes that pain and close individuals are a weakness that need to stripped in order to make a person stronger which he verbally made clear to his son and during their training sessions.
Kryptonian physiology: Normally, like all Kryptonians, Zeta-Rho's capabilities were no greater than a normal human of his physical conditioning. However, if he had been charged by the energy of a yellow sun metabolizing into his body, he would have become able to perform various inhuman feats. Ultimately, this never happened as Zeta-Rho was never exposed to a sun different to the Kryptonians' natural red one.