Has there ever been a superhero mythology better suited to television than Superman? From Smallville to Supergirl, Kal-El and his family have left their mark on the television landscape, and now even his grandpa is getting his own show. Krypton focuses on Superman's grandfather, Seg-El, who's in his mid-20s and fighting to restore the name of the royal family of El. However, even die-hard Superman fans may not be familiar with superhero's grandfather, as Seg-El barely appears in DC comics. His most notable appearance is in just one issue.
While the story of Krypton and its eventual destruction is essential to understanding the underlying tragedy of Superman, no films or television shows have explored the culture or structure of Krypton at length. The show Krypton seeks to remedy that, offering a Game Of Thrones-esque look at warring families and a revolution building against the rulers of the planet Krypton. While the Seg-El of the series seems to be the rebellious member of the family, there's no indication in the comics that the character ever had the triumphant youth seen in the show.
Instead, the Seg-El (spelled Seyg-El) seen in the comics, first introduced in Issue #3 of the World Of Krypton miniseries, is a staunch believer in rules and traditions to the point where he is seen scolding Jor-El, Superman's father, multiple times for minor discrepancies in his observance of the strict ceremonial rules of Krypton.
The World Of Krypton comics is a four-issue miniseries that covers the history of the planet Krypton, and specifically the El family lineage. The series, by John Byrne and Mike Mignola, launched in 1987, per Bleeding Cool, and features massive wars, conspiracies to destroy all of Krypton, and a twist on the Greek myth of Oedipus. Seyg-El doesn't appear until issue #3, and isn't even the central character of his own story. Instead, Seyg-El's purpose in the World Of Krypton comics is merely to bring Jor-el to the ruler of Krypton and inform him that he's been chosen to marry a woman named Lara.
Jor-El is found studying the history of Krypton, specifically the "War Of Clone Rights," a conflict caused by the fact that each Kryptonian was assigned three clones whose only purpose was to provide replacement body parts for the humans they were cloned by. The straw that broke the Kryptonian camel's back involved a woman named Nyra tricking her son into marrying a genetically-altered clone of herself, inspiring a fringe group called Black Zero to detonate a nuclear weapon on the planet and attempt to destroy human life on Krypton. Jor-El gets so swept up in the history of Krypton, that Seyg-El is forced to apologize to royalty on his son's behalf, and informs his son that he should be more respectful of authority. In a comic series full of dramatic events and complex characters, Seyg-El is little more than a cranky father who is punishing his son for wanting to learn about history.
While Seyg-El is one of the least interesting parts of the series that introduces him, Seg-El on Krypton will not be the rule-friendly father seen in World Of Krypton. In fact, with only a few other appearances in the character's share of canon, Krypton has the chance to create a whole new world around Seg-El, without worrying about being true to a comic book origin. Fans met Seg-El when he was already Jor-El's father, meaning that no prominent depiction of Seg-El's younger years existed before Krypton.
The show has the lineage of Superman comics to draw from, but Krypton has the opportunity to tell a story completely different from anything else seen in comic book history, let alone television.