For a number of reasons, Star Wars: The Rise of Skywalker sparked a great deal of controversy but Rey's lineage was arguably one of the big sticking points for some fans. In the film, we learn that Palpatine, Star Wars' greatest villain, had a son who married eventually had a child, Rey. Although there is som question as to whether or not this son was a clone, the sticking point for many fans is that Palpatine has had descendants.
However, that this isn't the first time in Star Wars history where Palpatine has a grandchild. In the '90s, there was a children's Star Wars book series -- with tenusous ties to Legends canon -- unofficially called "Jedi Prince," which written by Paul and Hollace Davids, illustrated by Karl Kessel, with covers by Drew Struzan. "Jedi Prince" is a series of six children's novels that stars Ken, a young boy who teams up with the heroes of the Rebel Alliance to fight the remains of Empire in the wake of Return of the Jedi. We later learn that Ken is, in fact, the grandson of Palpatine. Now, we're going to take a closer look at Ken, and how he compares to Rey Palpatine.
The Origins of Ken
Seven years before the Battle of Yavin, Ken was born to the "Jedi Princess" Kendalina and an unknown father. He was taken away from his mother after Stormtroopers murdered her, but enigmatic Jedi Masters took him away to raise him on the lost city of Yavin-IV, which happened to bring him at a young age in contact with the Rebel Alliance.
Without any love for the Empire, Ken grew up on stories of the Rebel Alliance, Obi-Wan Kenobi (who Ken believed himself named after), Luke Skwalker and Han Solo. He also learned of Palpatine and his "son" Triclops. This is the first instance in Star Wars canon of Palpatine ever being said to have a son, let alone it being well-known enough of a fact for Ken to learn growing up.
Ken taught himself how to use the Force, finding himself a natural user of it. Shortly after the Battle of Endor, Ken was ready to fight a faction of the Empire that was trying to rise up and fill the throne Palpatine vacated. An evil man known as Trioculous -- who Ken initially believed to be Palpatine's son -- had named himself the new Emperor and was searching for the Lost City. This naturally leads the Rebellion to the Lost City to intercept Ken first, which led to Ken joining the Rebellion to fight the new Emperor Trioculous.
Over the course of his adventures, Ken realized that not only Trioculous wasn't Palpatine's son, but that the real Triclops was still alive and, in fact, his secret father. This means that Ken is Palpatine's grandson. This disappointed Ken, who had convinced himself he was probably Obi-Wan Kenobi's son instead. With his fan-theory about his ancestry smashed, Ken was about to abandon being a part of the Rebellion, only for Luke to give a speech about the nature of his ancestry being secondary to his actions and good spirit. It also turns out that Triclops wasn't so evil himself, and he rebelled against his father by doing good.
The Similarities Between Ken and Rey
Almost immediately, it's clear that Ken and Rey bare an incredible amount in common. Much like Ken, Rey is taken from her parents, one of whom is the son of Palpatine, who rebelled against his father. The two both are introduced without last names. Rey and Ken both idolized the Rebellion and are snatched up by said Rebellion when the eyes of Palpatine's Heir Apparent comes looking for them, only to fight alongside their heroes Han and Luke. Like Ken, Rey is also adept with the Force, who is consumed by the mystery of her lineage. They even receive the same speech from Luke about heritage, though Ken is far more placated by Luke's words than Rey is, considering she then goes out to kill Palpatine herself.
The large difference between Ken and Rey, oddly enough, is that Ken serves as an even greater form of wish-fulfillment for young audiences than Rey does. While some accused Rey of being a "Mary Sue," Ken exhibits far more of these traits than Rey does. Rey lived a harsh life on a nowhere planet where she fought to survive, which taught her the skills necessary to survive. By contrast, Ken lived a fairly comfortable life in a lost city on the same planet as the Rebel Base. Ken is every child's dream character brought to life, while Rey is a slightly more cynical take on this same character archetype who also finds a chance to take vengeance on her grandfather.