A new theory has come into play regarding Superman and Lois's Earth-Prime's John Henry Irons and how he may have died at the hands of Lex Luthor. With having revealed its original villain, the Stranger, to be an alternate Earth version of a man named John Henry Irons, it begs the question of what happened to the Earth-Prime version. The Lex Luthor connection would be both a clever nod to the comics, where John Henry Irons became the superhero Steel in response to the actions of his corrupt employers and a way to further tie the Arrowverse John Henry Irons into the Superman family.
When the Stranger was introduced in the first episode of Superman and Lois, he was originally teased as being an alternate version of Lex Luthor, based on the fact that the artificial intelligence in his ship addressed him as "Captain Luthor." In retrospect, this made little sense, as the cosmic rules of the Post-Crisis Arrowverse do not allow doppelgängers from alternate realities to live on the same Earth. Then again, if there were anyone brilliant enough and devious enough to find a way around those rules, it would be a criminal mastermind like Lex Luthor. However, this theory was disproven in the Superman and Lois episode "Man of Steel," where it was revealed that the Stranger was a weapons engineer named John Henry Irons and not another world's Lex Luthor or a long-lost Luthor relative. The question of the Stranger's identity only opened the door to further questions, given that the Earth-Prime version of John Henry Irons was said to have died six years earlier.
While the Stranger revealing himself to be a doppelganger answered the question of whether or not John Henry Irons had been mysteriously resurrected, it still did not explain the mysterious circumstances under which Earth-Prime's John Henry Irons was said to have died in 2015. One theory, however, suggests itself upon analysis of what little is known about the lives of the Stranger and the John Henry Irons of Earth-Prime: he may have been a LuthorCorp employee who was murdered by Lex Luthor to ensure Luthor's secrets remained secret. This could have been either because Irons was threatening to expose Luthor's criminal activities to the world or simply because Lex didn't believe in trusting anyone who wasn't a relative.
The Background of The Stranger
The details of the Stranger's life were slowly unveiled over the first half of Superman and Lois season 1. The pilot episode revealed that he came from a world where Superman had turned on humanity. The Stranger claimed in the second episode that he had worked with General Sam Lane on his Earth and that the two had fought against Superman together. The Stranger was later revealed to be General Lane's son-in-law, having married his Earth's version of Lois Lane.
Most of what is known of the Stranger's life comes from the episodes "Man of Steel" and "Holding the Wrench," where he was revealed to have a daughter named Natalie, who helped him with constructing his armor and weapons. A collection of photos on his computer and a series of flashbacks confirmed his military background, even before he proved to be familiar with the layout of General Lane's headquarters and with the many Kryponite-based weapons created by Project 7734. Irons claimed to have created many of those weapons on his Earth.
It was implied that the Stranger worked for LuthorCorp at one time, as many of the parts that he and Natalie used in building his armor came in LuthorCorp cases. They also commandeered an artificial intelligence Lex Luthor had owned, but they were unable to get it to stop addressing the Stranger as if he were Lex Luthor. Irons also didn't deny having been paid to build things for Lex Luthor when Superman questioned him on his past as "a builder." Tellingly, he also claimed to be a former LuthorCorp employee when he was posing as a reporter named Marcus Bridgewater while trying to assist Lois Lane with her investigation into Morgan Edge.
The Background of Earth-Prime's John Henry Irons
Apart from not having married Lois Lane and not having worked with General Sam Lane, the Earth-Prime version of John Henry Irons seemed to have lived the same life as Superman & Lois's Stranger, up to a certain point. The Earth-Prime Irons was said, in "Holding the Wrench," to have been a U.S. Army Ranger who served two tours in Afghanistan as a Counter Insurgence Specialist First Class before being honorably discharged. He was also said to have made a name for himself in the private sector as a mechanical engineer and to have died under mysterious circumstances on July 7, 2015.
John Henry Irons' Comics Backstory
When Dr. John Henry Irons was introduced into the Superman comics during the Death and Return of Superman, he was a man on the run. Dr. Irons had previously been employed as a weapons designer by AmerTek Industries, a corrupt conglomerate with a reputation for coercing its employees to remain with the company by any means necessary. Taking the alias Henry Johnson, Irons moved across the country and found work in Metropolis as a construction worker. One day, shortly before Superman's apparent death at the hands of Doomsday, he saved Irons' life, catching him after he fell off a skyscraper while helping save another worker. Inspired by Superman's example and the realization that a gang terrorizing his neighborhood was using weapons based on his designs that AmerTek was selling in secret on the black market, Irons build himself a suit of power armor and became the Man of Steel. He later shortened this to just Steel, following Superman's resurrection.
Theory: John Henry Irons Was Silenced By Lex Luthor
While the John Henry Irons of Earth-Prime has yet to be confirmed as having worked for Lex Luthor, there is ample evidence that he, like the Stranger, might have been contracted to work for the famous billionaire. While Luthor is a technical genius, he's not above exploiting the work of others for his own ends, such as when he subverted his sister Lena's Project Non Nocere to brainwash most of the planet into loving him in the premiere episode of Supergirl season 6. It's worth noting that there are other alternate realities where John Henry Irons worked for Lex Luthor, such as the DC Animated Universe, where he designed a prototype battle suit for Luthor before resigning from his position as one of Luthor's chief engineers after he realized Luthor was more interested in using his work to show up Superman than saving lives. It may also not be a coincidence that the John Henry Irons of Earth-Prime died in 2015, around the same time Supergirl revealed herself to the world.
Substituting LuthorCorp for AmerTek Industries in the life of Earth-Prime's John Henry Irons would be a neat nod to the character's origins in the comics. It could also establish Irons' essentially heroic nature if we learned that his doppelgänger had intended to expose how Luthor was using his designs for evil, only to be assassinated before he could blow the whistle on Luthor's secret Kryptonite arsenal. This would also offer a novel way of continuing the Stranger's story on Superman and Lois in future seasons, by giving him and Superman another common enemy to unite against. It would also offer a perfect opening for Jon Cryer's Lex Luthor to enter the series as a regular antagonist.