Rusev made his NXT television debut on the May 30, 2013, episode (under the name Alexander Rusev), competing in a battle royal to determine the number one contender to the NXT Championship that was won by Bo Dallas. Rusev's first singles match on NXT came about on August 21, losing to Dolph Ziggler. Shortly thereafter, Rusev adopted Sylvester Lefort as his manager and formed a short-lived tag team with Scott Dawson named "The Fighting Legionnaires"; they feuded with the team of Enzo Amore and Colin Cassady. On the October 30 episode of NXT, Rusev ended his affiliation with Lefort by attacking him during a tag team bout.
Rusev proceeded to adopt Lana as his "social ambassador." In matches taped before his main roster debut, Rusev defeated main roster wrestlers Kofi Kingston, Xavier Woods, and Sin Cara in singles matches, which aired on NXT in January and February. Rusev continued to appear sporadically on NXT after joining the main roster in April 2014, making his final appearance on July 24, getting disqualified against NXT Champion Adrian Neville in a non-title match.
Rusev made his main roster debut at the Royal Rumble. The sixth entrant in the titular match, Rusev was eliminated by the joint effort of four wrestlers. After months of self-promotional videos and speeches by Rusev and his manager Lana, Rusev's return match on the main roster came on the April 7 episode of Raw, where he squashed Zack Ryder. In May, Rusev adopted a Russophillic, anti-American gimmick that saw him announced as having relocated to Russia, and as having been named "Hero of the Russian Federation". In the same month, his ring name was shortened to simply Rusev. Over the next several months, Rusev feuded with Xavier Woods and R-Truth (whom Rusev defeated at Extreme Rules in a two-on-one handicap match) and Big E (whom he defeated at Payback and at Money in the Bank), Jack Swagger (whom he defeated at Battleground and again at SummerSlam), Mark Henry (whom he defeated at Night of Champions) and Big Show (whom he defeated at Hell in a Cell). Lana dedicated Rusev's string of victories to President of Russia Vladimir Putin. On the October 6 episode of Raw, Rusev and Lana were confronted by The Rock in a surprise appearance, with The Rock driving Rusev from the ring after a verbal exchange.
On November 3, Rusev gained his first professional wrestling championship and became the first Bulgarian-born champion in WWE history when he won the United States Championship from Sheamus in a post-Raw match that aired on the WWE Network and proceeded to defeat him in a rematch via count-out. At Survivor Series, Rusev competed in a 10-man Survivor Series match as part of Team Authority but he was eliminated from the match by countout. Rusev and Jack Swagger once again feuded in December, leading to Rusev successfully defending the United States Championship against Swagger at TLC. At the Royal Rumble, Rusev entered the Rumble match at number 15, eliminating six other contestants and placing second overall. At Fastlane, Rusev successfully defended the United States Championship in a bout with John Cena. Rusev lost the United States Championship to Cena in a rematch at WrestleMania 31 after a miscommunication with Lana, ending his reign at 146 days and marking his first pinfall loss on WWE's main roster.
Rusev failed to regain the championship the following month at Extreme Rules in a Russian Chain match; during the match, Lana garnered a positive reaction from the crowd, leading to Rusev banishing her from ringside and causing dissension between the two. Rusev lost to Cena once more at Payback on May 17, 2015 in an "I Quit" match after Lana conceded the match on his behalf. On the post-Payback episode of Raw on May 18, 2015, Rusev ended his affiliation with Lana, who slapped him in response. On the May 25 episode of Raw, Rusev reverted to being billed from Bulgaria and began carrying the flag of Bulgaria to ringside. Later that same evening, Rusev unsuccessfully attempted to reconcile with Lana. Three days later on SmackDown, Rusev suffered a fractured foot in a bout with Ryback, rendering him unable to compete in the Elimination Chamber match for the vacant Intercontinental Championship at Elimination Chamber. Despite his injury, Rusev still appeared on television and made further attempts to reconcile with Lana. Lana then began a storyline relationship with Dolph Ziggler, while Summer Rae began an alliance with Rusev. On the June 29 episode of Raw, Rusev and Rae confronted Lana and Ziggler, leading to a fight between Rae and Lana. On the July 6 episode of Raw, Rusev and Rae once again confronted the couple, which turned out to be a ruse, as Rusev viciously attacked Ziggler after hitting him with his crutch and removed his ankle brace, revealing that his foot injury had healed. The attack resulted in Ziggler sustaining a bruised trachea in storyline and out of action indefinitely.
Rusev made his in-ring return on the following SmackDown, wrestling in shoes to avoid further foot injury, defeating Fandango. On the July 13 episode of Raw, Rusev answered John Cena's United States Championship open challenge. Rusev was then interrupted by both Kevin Owens and Cesaro, who also demanded a shot at the title. This resulted in a triple threat match, where the winner would face Cena, which Rusev won after pinning Cesaro, as Owens had left the match early on. Afterwards, Rusev defeated Cena by disqualification, when Owens assaulted Rusev. On the July 16 episode of SmackDown, Rusev suffered his second loss by pinfall during his tenure on the WWE main roster when he was defeated by Cesaro in a singles match. On the August 17 episode of Raw, Ziggler returned and attacked Rusev. This altercation prompted a match between Rusev and Ziggler at SummerSlam, which ended in a double countout due to interference from Lana and Rae, and after the match, Rusev and Rae brawled with Ziggler and Lana. On the October 5 episode of Raw, Rae proposed to Rusev in the storyline, but said he would not marry her until he had won another championship. On October 11, it was reported that Rusev had become engaged to Lana in real life. Lana then confirmed the engagement and it began being used in the storyline on television, which resulted in Rae breaking up with him on the October 12 episode of Raw. On the October 31 episode of Main Event, Rusev injured his bicep in a match with Neville, resulting in Neville winning the match via referee stoppage and Rusev being out of action.
Rusev returned on the November 23 episode of Raw, when he attacked Roman Reigns, and lost to him by disqualification after Sheamus and King Barrett attacked Reigns. A week later, on November 30 episode of Raw, Lana returned to the WWE, once again as a villainess, and reconciled with Rusev, during a Miz TV segment, and later in the same night, the two joined Sheamus' new stable The League of Nations. Throughout December, Rusev started a feud with Ryback, with Lana faking injuries to distract Ryback and help Rusev gain advantage. At TLC, Rusev defeated Ryback by technical submission to end the feud. Also in November, Rusev joined forces with Sheamus, King Barrett and Alberto Del Rio forming The League of Nations. The faction aligned themselves with Mr. McMahon and would continue to target WWE World Heavyweight Champion Roman Reigns. Rusev would enter the Royal Rumble match at the No. 2 spot, but he would be eliminated by Roman Reigns in one and a half minutes. On the March 14 episode of Raw, Rusev and Del Rio failed to win the WWE Tag Team Championship from The New Day. At WrestleMania 32, The League of Nations defeated The New Day, but after the match, The League of Nations was attacked by Mick Foley, Shawn Michaels and Stone Cold Steve Austin.
Following WrestleMania 32, on the April 4, episode of Raw, League of Nations members Sheamus and King Barrett were part of a losing effort against The New Day for the WWE Tag Team Championship after Barrett was pinned by Kofi Kingston, and following the match, Barrett was exiled from the group being called the "weak link", but moments after, The Wyatt Family went on to attack the remaining members of The League of Nations. On the April 28 episode of SmackDown, Rusev walked out on Sheamus after Del Rio walked out the both of them, thus disbanding The League of Nations.
On the May 2 episode of Raw, Rusev won a battle royal by last eliminating Zack Ryder to become the No. 1 contender for the United States Championship, which he won for the second time by defeating Kalisto at Extreme Rules via submission. Rusev defeated him in a rematch on the following week's SmackDown, after which he was confronted by Titus O'Neil, whom Rusev defeated at Money in the Bank to successfully retain the title. Rusev followed this with a successful third title defense against Cesaro and defeated O'Neil on the July 4 episode of Raw to retain the title. Rusev was then challenged by Zack Ryder, whom he defeated at Battleground for another successful title defense. During the 2016 WWE draft, Rusev, along with Lana, was drafted to Raw, taking the United States Championship with him. On the August 1 episode of Raw, after Rusev defeated Mark Henry to retain the title, Roman Reigns came out to confront Rusev. The following week on Raw, Reigns interrupted Rusev and Lana's wedding re-enactment, and issued a challenge to Rusev for the title. Rusev declined, and the two brawled, causing Lana to fall into a wedding cake. Backstage, Mick Foley told an angered Lana and Rusev that Rusev would defend the United States title against Reigns at SummerSlam. Later that night, Rusev successfully defended the title in an impromptu match against Cesaro, who felt that he should also have a shot at the title. At SummerSlam, the match did not start after Rusev attacked Reigns before the bell rung and the two brawled outside of the ring, with Rusev suffering kayfabe injured ribs. After costing Reigns the opportunity of becoming a No. 1 contender for the Universal Championship, Rusev defended the United States Championship against Reigns in a match at Clash of Champions, which he lost, ending his reign at 126 days. Rusev would then get his rematch at the Hell in a Cell pay-per-view in a Hell in a Cell match, which he would be unsuccessful.
On the November 21 episode of Raw, after being locked out of his locker room, Enzo Amore would run into Lana in the hallway before being angrily confronted by Rusev. Rusev would challenge Amore to a match later that night, quickly defeating him. The following week on Raw, Amore would defeat Rusev by disqualification. At Roadblock: End of the Line, Rusev would face Amore's tag partner, Big Cass, defeating him by countout. The following night on Raw, Rusev would face Cass again, this time defeating him by disqualification. That same night, Amore would have to attend sensitivity training from the incident on the November 21 episode of Raw. At the training, Amore would be attacked by Rusev and his new ally, Jinder Mahal. On the January 2, 2017 episode of Raw, Rusev teamed with Mahal in a 2-on-1 handicap match, defeating Big Cass. At Royal Rumble, Rusev would enter the Rumble match at number eighteen, lasting over 20 minutes before being eliminated by Goldberg. On the February 27 episode of Raw, Rusev and Mahal began to show tension after Rusev inadvertently distracted Mahal, causing the two to lose to The New Day. At Fastlane, general manager Mick Foley placed Rusev and Mahal in singles matches that night after Mahal revealed his desire to return to singles competition. Rusev and Mahal both lost their respective matches against Big Show and Cesaro. Both Rusev and Lana disappeared from television following Rusev requiring surgery for an injury.
On April 11, Rusev was moved to SmackDown brand as part of the Superstar Shake-up. On the April 25 episode of SmackDown Live, Rusev made his first appearance on WWE programming since Fastlane, appearing via satellite, and declared that he would not make his debut on SmackDown unless he was given a WWE Championship match at the Money in the Bank pay-per-view on June 18. He was not granted his request, but on the July 4 episode of SmackDown Live, he made his first appearance for the brand and confronted the returning John Cena, setting up a flag match for Battleground, which he lost.
In August, Rusev started a feud with Randy Orton and was defeated by Orton at SummerSlam in 10 seconds. He got his revenge on the following episode of SmackDown Live, and was given the key to his legitimate hometown of Plovdiv. The mayor granted him the key to the city, as witnessed by Aiden English. However, both English and Rusev were attacked by Orton. That day was stated as "Rusev Day" and in following SmackDown Live episodes, Rusev would state that every day was "Rusev Day", with the crowd chanting its name whenever Rusev and English were present. At Hell in a Cell, Rusev lost to Orton again, thus ending their feud. Following the loss, Rusev and English wrestled as a tag team, participating in a fatal four-way tag team match for the SmackDown Tag Team Championship at Clash of Champions also involving The New Day, Chad Gable and Shelton Benjamin and the champions The Usos. They were unsuccessful in winning. On the March 27, 2018 episode of SmackDown Live, Rusev teamed with Jinder Mahal to defeat Bobby Roode and Randy Orton, subsequently adding him to the United States Championship match at WrestleMania 34. At the event, Rusev was pinned by Mahal, losing the match. At the Greatest Royal Rumble event, he faced The Undertaker in a Casket Match, but he lost. On the May 8 episode of SmackDown Live, Rusev defeated Daniel Bryan to qualify for the Men's Money in the Bank ladder match, which was won by Braun Strowman. On the following episode of SmackDown, he won a gauntlet match to become the number one contender for AJ Styles' WWE Championship at Extreme Rules. At the event, he was defeated by Styles.
In July, Rusev Day started a feud with Andrade "Cien" Almas and Zelina Vega, thus turning them face in the process for the first time in his career. Rusev and Lana lost a mixed tag team match to Almas and Vega at SummerSlam but defeated them in a rematch on the August 21 episode of SmackDown Live. On the September 4 episode of SmackDown Live, Rusev and English defeated The Usos and Sanity in a triple threat match to face The Bar, whom they defeated on the following week's SmackDown Live to earn a SmackDown Tag Team Championship match against The New Day at Hell in a Cell, which they lost. On the September 18 episode of SmackDown Live, Rusev lost to Shinsuke Nakamura for the United States Championship after a distraction by English, after which English turned on Rusev by attacking him, thus ending their alliance. On the October 23 episode of SmackDown Live, Rusev defeated English, ending their feud.
After failing to win the United States Championship from Nakamura at Crown Jewel, Rusev finally managed to capture the United States Championship for a third time in his career on the December 25 episode of SmackDown. On January 27, 2019, he lost the title back to Nakamura on the Royal Rumble pre-show. Two days later on SmackDown Live, Rusev confronted R-Truth, who had just defeated Nakamura for the United States Championship, and pushed him into defending his newly-won title against him, but Truth retained his title. After the match, Nakamura attacked Truth, and Rusev joined him in attacking Truth, thus turning heel again in the process and later forming a tag team with Nakamura. On the Fastlane pre-show, Nakamura and Rusev were defeated by The New Day. At WrestleMania 35, Nakamura and Rusev would compete in a fatal four-way tag team match for the SmackDown Tag Team Championship, but were unsuccessful. The duo returned during the 51-Man Battle Royal at the 2019 Super Showdown, but they were both eliminated during the match. Following the Super Showdown loss, Rusev and Lana subsequently disappeared from television.
Rusev made his return on September 16, 2019 edition of Raw, sans Lana and sporting a new mustachioed look, where he quickly defeated Mike Kanellis. On the September 30 season premiere episode of Raw, Rusev came to the aid of Seth Rollins after being attacked by Randy Orton and Baron Corbin, and was subsequently made as the second person on Team Hogan for Crown Jewel. Later, Charly Caruso asked Rusev where Lana was, but he gave no response. He then challenged Rollins for a Universal Championship match later that night. The match ended in a no-contest when Bobby Lashley made his return and called someone out, who was revealed to be Lana. The two would then make out and Rusev was forced to watch them. As part of the 2019 draft, Rusev was drafted to Raw. At Crown Jewel, Team Hogan defeated Team Flair as Roman Reigns pinned Randy Orton.
On the November 4, episode of Raw, Lashley turned down Rusev's challenge for a one-on-one match stating a torn groin as the reason. Drew McIntyre and Randy Orton then showed up to face Rusev in place of Lashley and Rusev was put in a handicap match against the two of them. During the match, Lashley interrupted by attacking Rusev with his crutch thus ending the match via disqualification and beginning a two-on-one attack alongside Orton. Orton hit Rusev with an RKO while Lashley attacked a downed Rusev. The attack was thwarted by the arrival of Ricochet, who came to the aid of Rusev and cleared the ring. On the November 11 episode of Raw, Lana came out to the ring to deliver her "shocking confession" that she was pregnant and she was sure that the baby was Rusev's. Rusev then showed up to the ring to calm things down but an angry Lana slapped him across the face multiple times. They were then interrupted by Lashley who ambushed Rusev after Lana raked him across the eyes. It was then implied that the whole thing was a bluff as Lashley and Lana made out near a downed Rusev. On the November 25 episode of Raw, Rusev interrupted Lashley during his match with Titus O'Neil by attacking O'Neil and giving Lashley a win via disqualification. Rusev then proceeded to punch Lashley out of the ring with Lana screaming at him to stop. He sent Lashley into the ring steps before driving him off into the barricade. He then proceeded to beat down Lashley through the entrance ramp while thwarting his attempts to make a comeback and drove him off into the LED panels. He then cleared the announce table to slam Lashley through it but the police showed up and restrained him with handcuffs as he violated Lana's restraining order. As Lana checked on a downed Lashley, Rusev broke free from the hold of the police and shoulder blocked Lashley off the stage through some tables placed beneath it. He then proceeded to kick a steel structure over Lashley before being escorted away backstage by the police. On the December 4 episode of Raw, Rusev interrupted Lana and Lashley as they celebrated the victory of Lashley over Kevin Owens following an interruption from the AOP. Rusev peoceeded to attack Lashley but it proved to be brief as the Nashville Police showed up and arrested Rusev due to another violation of Lana's restraining orders. Lana and Lashley were subsequently arrested as well when Lashley shoulder blocked the officer incharge and Lana slapped him across the face. On the December 9 episode of Raw, Lashley interrupted Rusev and Lana inside the ring as they finalised their kayfabe divorce by saying that he would marry Lana as soon as the divorce was finalized. Rusev in response said that he wanted a match with Lashley in exchange for the divorce in a match of his choosing. He then proceeded to attack Lashley after signing the divorce papers by applying a belly-to-belly suplex on the table placed in the centre of the ring. Lashley defeated Rusev in a tables match at the December 15 TLC: Tables, Ladders & Chairs pay-per-view event. On the December 24 episode of Raw, Rusev defeated No Way Jose in a singles match. After the match, he proclaimed that he felt liberated after his separation from Lana while also promising revenge for his loss at TLC. On the January 13 episode of Raw, Lashley defeated Rusev in a singles match following interference from Lana and Liv Morgan. After the match, a mixed tag team match was scheduled between teams of Rusev and Morgan and Lana and Lashley. The mixed tag team of Rusev and Morgan was defeated by Lana and Lashley in the January 20 episode of Raw.
On April 15, 2020, Rusev was released from his WWE contract.