On May 22, 2013, Amore debuted on NXT television as a heel, being described as a "stereotypical cocky, Jersey Shore loudmouth", where he was squashed by Mason Ryan. On the July 3 episode of NXT, Amore went on to form an alliance with Colin Cassady, who had also lost to Ryan, and they named themselves "the realest guys in the room". Despite Amore and Cassady's alliance, Ryan easily defeated them in consecutive singles matches in July, but lost to them in a handicap match. After the feud with Ryan, Amore and Cassady went on to feud with Alexander Rusev, Scott Dawson and their manager Sylvester Lefort, turning face in the process. On the September 25 episode of NXT, Amore and Cassady participated in a gauntlet match for a future shot at the NXT Tag Team Championship; they started the match, first defeating CJ Parker and Tyler Breeze, then defeating Rusev and Dawson but lost to The Ascension (Konnor and Viktor). In November 2013, Amore suffered a broken leg while training.
Amore returned on June 26, 2014 episode of NXT, saving Cassady from an attack from Sylvester Lefort and Marcus Louis. In early August, Amore and Cassady participated in the NXT Tag Team Championship tournament. They defeated Jason Jordan and Tye Dillinger in the first round, but were eliminated by The Vaudevillains (Aiden English and Simon Gotch) in the second round. Lefort and Louis then renewed their rivalry with Amore and Cassady by attacking them and shaving Amore's beard. As a result, Amore challenged Lefort to a match with the loser's hair as forfeit at NXT TakeOver: Fatal 4-Way which Amore won, but Lefort ran away, leaving his partner Louis to lose his hair and eyebrows. Amore and Cassady then formed an alliance with the debuting Carmella. The duo had accidentally cost Carmella her hairdressing job, causing her to demand to get a job as a wrestler. Carmella had her televised in-ring debut on the October 16, 2014 episode of NXT. On the March 11, 2015 episode of NXT, Amore and Cassady defeated The Lucha Dragons to become the number one contenders for the NXT Tag Team Championship. At NXT TakeOver: Unstoppable, Amore and Cassady faced Blake and Murphy for the title in a losing effort after interference from Alexa Bliss. In December, Amore and Cassady began a feud with Dash and Dawson, where they challenged them for the NXT Tag Team Championship at both NXT TakeOver: London and Roadblock unsuccessfully.
On the Raw after WrestleMania 32, Amore and Cassady debuted on the main roster and confronted The Dudley Boyz. A week later on SmackDown, Amore and Cassady defeated The Ascension in a tournament to determine the number one contenders for the WWE Tag Team Championship. The team went on to defeat The Dudley Boyz on the following week's Raw in the semi-final of the tag team tournament, advancing them to the finals. In the finals, they faced the Vaudevillains at Payback, with the match ending in a no contest after Amore suffered a legitimate concussion during the match. At Money in the Bank, Enzo and Cass faced The New Day, The Vaudevillains and Luke Gallows and Karl Anderson in a fatal-four way tag team match for the WWE Tag Team Championship, in which The New Day retained their titles. On the July 4 episode of Raw, Enzo and Cass helped John Cena, who was getting attacked by The Club (AJ Styles, Luke Gallows and Karl Anderson) involving themselves in the feud between Cena and The Club. At Battleground, Enzo and Cass teamed with Cena to defeat The Club in a six-man tag team match.
On July 19 at the 2016 WWE draft, Enzo and Cass were drafted to the Raw brand. Enzo and Cass then proceeded to feud with Chris Jericho and Kevin Owens, which culminated at SummerSlam, where the two lost to Jericho and Owens. On the November 7 episode of Raw, Enzo and Cass joined Team Raw for the Survivor Series tag team elimination match at Survivor Series, during which Team Raw defeated Team SmackDown. On the November 21 episode of Raw, after Amore was locked out of the locker room naked by Cass as a practical joke and ran into Lana in the hallway, her husband Rusev challenged Amore to a match later that night, in which Amore was quickly defeated. On the December 5 episode of Raw, after Amore stood up for Lana after seeing her and Rusev argue backstage, Lana invited Amore to her hotel room. Later that night, this was revealed to be a trap when Rusev attacked Amore in the hotel room. Over the following weeks, Enzo and Cass feuded with Rusev and Jinder Mahal. On January 29, 2017, Amore participated in the Royal Rumble match, entering at number 27 but was eliminated by Brock Lesnar. At WrestleMania 33, Enzo and Cass competed in a fatal-four way ladder match for the Raw Tag Team Championship against defending champions Luke Gallows and Karl Anderson, Cesaro and Sheamus, and the returning The Hardy Boyz, where The Hardy Boyz emerged victorious. The following night on Raw, Amore and Cass were defeated by Cesaro and Sheamus in a tag team match to determinate the number one contenders for the Raw Tag Team Championship.
On the May 22 episode of Raw, Amore was found unconscious backstage after being attacked from behind by an unknown assailant, and again the following week. Big Cass went on to accuse The Revival, who had been seen in the background in the aftermath of the attacks. On the June 5 episode of Raw, Cass was found knocked out backstage in the same fashion as Amore was. Later, Cass claimed he was not cleared to wrestle, so Amore teamed with Big Show in a match against Luke Gallows and Karl Anderson, which they won. The following week, Cass was again found knocked out backstage. He claimed the attacker had to have had a giant fist and blamed Big Show, who denied having been the attacker. On the June 19 episode of Raw, General Manager Kurt Angle attempted to expose the attacker before security footage found by Corey Graves revealed that Cass had faked his own attack in order to lure away suspicion. Cass admitted to this, expressing his frustration during his time teaming with Amore. Cass then attacked Amore, thus disbanding the team. On the June 26 episode of Raw, Amore called out Cass to the ring and the two seemingly reconciled; however, Cass again viciously attacked Amore on the stage. At the Great Balls of Fire pay-per-view, Amore was defeated by Cass. At SummerSlam, Cass defeated Big Show while Amore was suspended above the ring inside a shark cage. During the match, Amore escaped from the shark cage, but was quickly attacked by Cass. The next night, on the August 21 episode of Raw, Amore challenged Cass to a Street Fight, which he won after the referee stopped the match after Cass suffered a legitimate knee injury.
On the August 22 episode of 205 Live, Amore debuted in the cruiserweight division and began a feud with Cruiserweight Champion Neville. On the September 5 episode of 205 Live, Amore earned a title opportunity against Neville, winning a fatal five-way elimination match also involving Cedric Alexander, The Brian Kendrick, Gran Metalik and Tony Nese. At No Mercy on September 24, Amore defeated Neville with a low blow to win the Cruiserweight Championship. The following night on Raw, Amore closed the show with a "championship celebration", where he insulted the cruiserweight division and stated that he made 205 Live "relevant" and that the 205 Live roster was "jealous" of his accomplishments, turning heel for the first time since 2013. He also showed a signed clause by General Manager Kurt Angle that if any cruiserweight touched him, they would lose their title opportunities. The week after on Raw, Amore revealed another paper clause stating that any cruiserweight that tried to touch him would be fired. Subsequently, Kalisto was introduced as the newest member of the cruiserweight division and attacked Amore. On the October 9 episode of Raw, Amore lost the Cruiserweight Championship to Kalisto in a lumberjack match. However, he regained the title in the rematch at TLC: Tables, Ladders & Chairs on October 22, via an illegal thumb shot to the eye behind the referee's back. On the Survivor Series pre-show on November 19, Amore successfully defended the title against Kalisto. This was his last WWE pay-per-view appearance. In early January 2018, Amore was unable to compete due to sickness.
Amore was suspended from WWE on January 22, 2018. As a result, his scheduled title defense against Cedric Alexander at the Royal Rumble was canceled. The next day, Amore was fired from WWE and the title was vacated.