Sami Zayn signed to WWE on January 9, 2013, where he worked in their developmental territory NXT. On August 12, 2014, Kevin Owens signed with WWE and was also sent to NXT and debuted at NXT TakeOver: R Evolution in the opening match, defeating CJ Parker. In the main event, Zayn defeated Adrian Neville to win the NXT Championship. After a long celebration with the roster, Owens turned on Zayn, delivering a powerbomb on the apron and re-igniting their feud. On February 11, 2015 at NXT TakeOver: Rival, Owens won the title from Zayn via ref stoppage after continuously powerbombing Zayn.
In May 2015, Owens was brought up to the main roster, followed by Zayn the following year. On the May 16, 2016 episode of Raw, Owens and Zayn were placed in a tag team match to face Cesaro and The Miz in a winning effort, but Owens would attack Zayn immediately after the match. The two would go on to have a grudge match at the Battleground pay-per-view, where Zayn defeated Owens. Both would be drafted to the Raw brand during the 2016 WWE draft, but were traded to the SmackDown brand during the 2017 WWE Superstar Shake-up.
On October 8, 2017, at Hell in a Cell, Zayn helped Owens defeat SmackDown Commissioner Shane McMahon in the main event, turning Zayn heel for the first time in his career and reuniting with Owens in the process. On the October 10 episode of SmackDown Live, Zayn said that Owens was right all along and called Owens his "brother". On the October 17 episode of SmackDown Live, Owens and Zayn defeated Randy Orton and Shinsuke Nakamura in a tag team match after Zayn hit a low blow on Orton. On the Survivor Series kickoff show, Owens and Zayn defeated Breezango (Tyler Breeze and Fandango). Later that night, they attacked Shane McMahon during the 5-on-5 Survivor Series Interbrand elimination match, which ultimately lead to Team SmackDown's defeat. On the November 28 episode of SmackDown, Owens defeated Orton in a no disqualification match after interference from Zayn, who was originally banned from ringside. On the December 5 episode of SmackDown Live, Zayn lost to Orton with Owens handcuffed to the ring ropes.
At Clash of Champions on December 17, Owens and Zayn faced Orton and Nakamura in a tag team match with their jobs on the line and both Shane McMahon and SmackDown General Manager Daniel Bryan as referees. After a fast count from Bryan, Owens and Zayn won the match, thus keeping their jobs. Following Clash of Champions, Owens and Zayn would embark on a feud with WWE Champion AJ Styles, facing him at the Royal Rumble in a handicap match and at Fastlane in a six-pack challenge, also including Baron Corbin, Dolph Ziggler, and John Cena, failing both times. During the Fastlane match, Owens and Zayn's rivalry with Shane McMahon intensified when Shane, who was sitting at ringside, constantly interfered and broke up pinfalls attempted by both Owens and Zayn. This led to a match at WrestleMania 34 against the team of Shane McMahon and the SmackDown General Manager Daniel Bryan, who made his in-ring return after years of retirement. At the event, Zayn submitted to Bryan's Yes! Lock. After they lost, they joined Raw, where they wrestled several tag team matches until Money in the Bank. After the event, it was reported that Zayn had to undergo surgery to fix torn rotator cuffs on his knee and shoulder, thus splitting the team.
On the June 4, 2019 episode of SmackDown Live, Owens and Zayn would reunite to face The New Day in a losing effort. At Stomping Grounds, they defeated The New Day. After the Stomping Grounds event, the duo of Owens and Zayn drifted apart again, after Owens turned face and reignited his feud with Shane McMahon.
In March 2021, Zayn began a gimmick as a deranged conspiracy theorist that believed the WWE was holding him down. Soon after, Zayn reignited his feud with Owens after Zayn tried unsuccessfully to convince Owens to believe in his conspiracy theories. Owens then challenged Zayn to a match at WrestleMania 37, which Zayn accepted. At WrestleMania, Owens defeated Zayn. After Zayn interfered with Owens and Big E’s tag team match against Apollo Crews and Commander Azeez on the June 18 edition of SmackDown, Owens demanded a match against Zayn at Hell in a Cell, which Zayn won. On the July 2 episode of SmackDown, Owens defeated Zayn in a rematch, which was contested as a Last Man Standing match to qualify for the men's Money in the Bank ladder match.
After joining The Bloodline in 2022 as the "Honorary Uce", Zayn began a feud with Owens by the start of 2023 and wrestled each other on the January 20 episode of SmackDown, only for The Usos and Solo Sikoa to interfere. During the Royal Rumble main event, Roman Reigns, who questioned Zayn's loyalty in recent weeks, retained the Undisputed WWE Universal Championship against Owens and proceeded to have the rest of The Bloodline attack Owens after the match. Zayn refused to join the beatdown and eventually hit Reigns with a steel chair, prompting the rest of The Bloodline to beat down Zayn and thus ejecting him from the group while Jey Uso walked out. On the February 3 episode of SmackDown, Zayn attacked Reigns and challenged him to a match for the Undisputed WWE Universal Championship at Elimination Chamber, which Reigns accepted. Zayn failed to win the title and was assaulted by Reigns and Jimmy Uso following the match until Owens appeared and saved Zayn. On the following episode of Raw after Elimination Chamber, Zayn offered an olive branch to Owens and proposed that they team up to bring down The Bloodline together, but Owens rejected it.
On the March 17 episode of SmackDown, Cody Rhodes invited Owens and Zayn to hash it out so that they can reunite to fight against The Bloodline, but Owens again declined to team up with Zayn. Later that night, Zayn confronted Jey Uso in the ring and was beaten up by The Usos. Owens ran out to save Zayn and embraced him, officially reuniting in the process. On the March 20 episode of Raw, Owens and Zayn challenged The Usos to a match for the Undisputed WWE Tag Team Championship at WrestleMania 39, which The Usos accepted. At WrestleMania 39, they defeated The Usos to win the Undisputed WWE Tag Team Championships, ending the Usos' historic Undisputed Tag Team Championship reign. Owens and Zayn were drafted to the Raw brand in the 2023 WWE Draft. At Night of Champions, Owens and Zayn retained their Undisputed Tag Team Championship against The Bloodline (Roman Reigns and Solo Sikoa). They lost the titles to The Judgment Day's Finn Bálor and Damian Priest in a Pittsburgh Steel City street fight at Payback in September after interference from Dominik Mysterio, Rhea Ripley, and JD McDonagh, ending their reign at 154 days. They were unsuccessful in a rematch for the titles on the September 25 episode of Raw. Also at Payback, Cody Rhodes got Jey Uso—who was on SmackDown and had quit WWE shortly before Payback—reinstated as a member of Raw and it was revealed that someone was traded to SmackDown for Jey. The following month on the October 13 episode of SmackDown, new SmackDown General Manager Nick Aldis revealed that Owens had been traded to SmackDown for Jey, in turn splitting the tag team of Owens and Zayn.