As late as March 2014, the main antagonist of Star Wars: The Force Awakens was only known to the production team as "Jedi Killer" and had gone through numerous unapproved design attempts (one of which was reused for Captain Phasma).

[10] According to The Force Awakens costume designer Michael Kaplan: I don't know if it was the kind of spaghetti type lines on it or what, but the next time J.J. [Abrams] came by that was what we presented to him and he loved it.

[11] Kylo Ren was first seen from behind, but still not named, in the 88-second The Force Awakens teaser trailer released by Lucasfilm on November 28, 2014,[12][13] wielding a jagged red lightsaber with a crossguard.

[20] Driver explained that his goal was "to forget you're in Star Wars and treat it like any other job that's filled with moments and problems", because from the perspective of the characters living within the film's universe, "Darth Vader is real.

"[9][d] Robbie Collin of The Telegraph described Ren as "a hot-headed, radicalised dark side extremist, whose red lightsaber splutters and crackles as violently as his temper".

[24] Melissa Leon of The Daily Beast describes Ren's use of the Force as "formidable", citing his ability to stop a blaster shot mid-air, immobilize victims and probe their minds against their will.

According to Lev Grossman, who interviewed the actor in the lead-up to The Rise of Skywalker, Driver reported that "both Han Solo and Leia were way too self-absorbed and into this idea of themselves as heroes to really be attentive parents in the way a young and tender Ren really needed.

[29] He later clarified: "J.J. Abrams told me when I met him for the first time that I should imagine a journey of a character completely opposite to Darth Vader...someone who starts as a child and becomes a man over the course of three movies.

"[40]Kylo Ren was introduced in the 2015 film The Force Awakens as a warlord of the First Order, a tyrannical regime that arose from the remains of the Galactic Empire.

After arriving on Jakku to retrieve a map containing the coordinates where Luke Skywalker can be found, Ren kills an elderly man named Lor San Tekka.

Rey and Chewbacca escape with the unconscious Finn as Snoke orders General Hux to bring Ren to him to complete his training.

While Ren vanquishes the vision of Luke, he finds himself unable to fully banish the image of his parents, who plead with him to return to the light.

On a mission to the planet Elphrona to investigate an ancient Jedi outpost with Luke and Lor San Tekka, Ben telepathically communicates with Snoke.

After Ren agrees to retreat, he unmasks and, placing his mask on the ground, offers Ben an open invitation to the group's ranks if he ever desires in the future.

Later, Ben bleeds his blue Kyber crystal, cracking it in the process, and forges himself a crossguard lightsaber as the voice of Snoke asks him what his new name is.

Kylo Ren is a point of view character in the 2015, 2017, and 2019 novelizations of the Star Wars sequel trilogy by Alan Dean Foster, Jason Fry, and Rae Carson.

[44] According to the book Skywalker: A Family at War by Kristin Baver, as the son of Princess Leia, Ben Solo would have inherited the title of "Prince of Alderaan" if the planet and the royal House of Organa not been destroyed by his grandfather, Darth Vader, and Empire prior to his birth.

[45] According to the 2016 novel Star Wars: Bloodline by Claudia Gray, as well as the 2017 Chuck Wendig novel Star Wars: Aftermath: Empire's End, due to the destruction of Alderaan, Princess Leia gave birth to Ben on Chandrila, the home planet of Mon Mothma, as well as the temporary capital of the New Republic.

[68] Kylo appears in Star Wars Battlefront II, voiced by Matthew Wood and Roger Craig Smith, masked and unmasked respectively.

In the game, Kylo interrogates Del Meeko about Lor San Tekka's location (who possess the map to Luke Skywalker) using his Force abilities.

[69] In January 2016, Driver reprised the role for a Star Wars: Undercover Boss sketch on Saturday Night Live, with Kylo Ren disguising himself as a radar technician named "Matt" to determine what the Starkiller Base employees really think of him.

[1] Kylo Ren appears as a walk-around character within Star Wars: Galaxy's Edge at Disneyland and Disney's Hollywood Studios.

[73] In November 2019, Ichikawa Ebizō XI starred in a kabuki production that depicted events in Ren's life from The Force Awakens and The Last Jedi.

[77] Many reviewers commended Ren's conflicted nature and depth, as well as his costume design, and noted there were many places the character could be taken in future installments.

[78][79][80] Peter Bradshaw of The Guardian praised the character and the actor alike, saying, "He is gorgeously cruel, spiteful and capricious – and unlike the Vader of old, he is given to petulant temper tantrums, with his lightsaber drawn.

[82] Robbie Collin of The Daily Telegraph wrote, "To describe Kylo Ren as this film's Vader would be accurate in a sense...but it would also be to undersell the deep ingenuity with which this astonishing character has been crafted by Abrams, Kasdan and Arndt, and also the wells of emotional tumult Driver invests in him.

[25] JJ Abrams told Entertainment Weekly, "It was a great joy to work with Adam Driver on this role, because he threw himself into it in a deep and remarkable way.

"[9] Todd McCarthy of The Hollywood Reporter noted, "Ren is given a pronounced inferiority complex, a clever bad guy twist that could be taken to interesting places both in the writing and performance.

"[83] Peter Travers of Rolling Stone wrote, "The bald-faced attempt to clone Darth Vader, one of the greatest badasses in film history, is clankingly obvious, but Driver, masked and unmasked, gives him hypnotic and haunting contours.

Just like the real-life young men with minds clouded by fear, hate, and anger who commit unspeakable acts in our world every day ...all the visual cues that leave the character open to criticisms of not being 'evil' enough—are all signs of Ren's struggle between the Dark Side and the Light.