On February 24, 2021, Williams signed a developmental contract with WWE and was assigned to the WWE Performance Center and subsequently the NXT brand. Later that year, he made his first appearance on the September 14 episode of NXT as the bodyguard of Carmelo Hayes. Williams made his in-ring debut on the October 5 episode of NXT, teaming with Hayes in a fatal four-way elimination tag team match for the NXT Tag Team Championship, where they lost to MSK (Nash Carter and Wes Lee).
Throughout 2022 and 2023, Williams accompanied Hayes in most matches. On the August 1, 2023 episode of NXT, Williams told Hayes that they needed to part ways so he could achieve his own accomplishments, amicably breaking up the Trick Melo Gang. On the September 26 episode of NXT, Williams became the number one contender to the NXT North American Championship by defeating Axiom, Dragon Lee and Tyler Bate in a fatal four-way match. A few days later at NXT No Mercy, Williams won the title by defeating The Judgment Day's "Dirty" Dominik Mysterio. However, just three days later on NXT, Williams lost the title back to Mysterio after interference from Mysterio's Judgment Day stablemates Finn Bálor, Damian Priest, and Rhea Ripley, as well as their associate JD McDonagh, marking it the shortest reign in the title's history.
On the October 17 episode of NXT, Williams was slotted into the triple threat match between Hayes, Dijak and Baron Corbin to make it a fatal four-way match for an NXT Championship opportunity against Ilja Dragunov at NXT Halloween Havoc; this announcement caused a rift between Williams and Hayes. Before the match started, Williams was found attacked backstage and had to be taken to a hospital. Hayes went on to defeat Dijak and Corbin for the title opportunity. At NXT Halloween Havoc, during night two, Williams returned during the NXT Championship match and cost Hayes the title, staring him down after the match. On the November 14 episode of NXT, Williams defeated Joe Coffey to qualify for the Iron Suvivor Challenge at NXT Deadline. At NXT Deadline on December 9, Williams won the men's Iron Survivor Challenge to earn an NXT Championship match against Dragunov at NXT New Year's Evil. At New Year's Evil on January 2, 2024, it was announced that Dragunov was not medically cleared to compete. Williams instead was put in a match against Grayson Waller with his Iron Survivor Challenge title match on the line by Hayes. Williams went on to defeat Waller after interference from Kevin Owens. On the January 16 episode of NXT, Dragunov returned from his injury and informed Williams that their title match would take place at NXT Vengeance Day. On the same edition of NXT, Williams and Hayes defeated Edris Enofé and Malik Blade in the first round of the Dusty Rhodes Tag Team Classic. Williams made his SmackDown debut on January 26, saving Hayes from a beatdown by A-Town Down Under (Grayson Waller and Austin Theory). On the January 30 episode of NXT, Williams and Hayes defeated Latino World Order's Joaquin Wilde and Cruz Del Toro to advance to the finals of the Dusty Rhodes Tag Team Classic.
At NXT Vengeance Day on February 4, Williams and Hayes lost to Baron Corbin and Bron Breakker in the finals of the Dusty Rhodes Tag Team Classic. Later that night, Williams failed to win the NXT Championship from Ilja Dragunov. After the match, Hayes attacked Williams with a steel chair, ending their partnership. On the following episode of NXT, Hayes revealed that he was the one who attacked Williams back in October 2023. At NXT Roadblock on March 5, Williams' entrance music was used by The Family's Tony D'Angelo to distract Hayes during their match to determine the number one contender for the NXT Championship at NXT Stand and Deliver. After D'Angelo defeated Hayes, Williams made his return and attacked Hayes. The following week on NXT, Williams challenged Hayes to a match at NXT Stand and Deliver, which was made official a few days later. Williams went on to defeat Hayes at the event on April 6. On the following episode of NXT, Williams called out Dragunov to challenge him for the NXT Championship. Dragunov agreed to a title match at Spring Breakin' on the condition that Williams would leave NXT if he lost, which Williams accepted. Hayes then attacked Williams from behind and told him that they would face each other the following week in a steel cage match, which Williams would win, ending the feud. During week one of Spring Breakin', Williams defeated Dragunov to capture the NXT Championship for the first time in his career.
Following the win, The Meta-Four's Lash Legend would appear and reveal that the stable had a secret that would derail his title reign. On the May 7 episode of NXT during Supernova Sessions, Noam Dar said that in a match between them which was won by Williams, Dar's leg was under the ropes, which should have broken the pinfall, and called Williams a fraud. Dar proceeded to attack Williams shortly after Legend revealed that she was having a relationship with Williams. On the following week, Dar was found attacked by an unknown assailant. Later that night, Williams assisted Je'Von Evans in defeating Oro Mensah, and a partnership between Williams and Evans was formed. On the May 28 episode of NXT, Williams and Evans defeated Gallus' Joe Coffey and Mark Coffey in a tag team match. After the match, Williams was attacked by a debuting Ethan Page, who revealed himself as Dar's attacker. At NXT Battleground on June 9, Williams successfully defended the NXT Championship against Page. At NXT Heatwave on July 7, Williams lost the title to Page in a fatal four-way match also involving Je'Von Evans and Shawn Spears, the former of whom Page pinned, ending his reign at 75 days.
After losing the NXT Championship, Williams got into with a bitter feud with Pete Dunne after Dunne derided Williams for seeking advice to recapture the NXT Championship. This led to a match between the two during week two of The Great American Bash on August 6, where Dunne won. Williams retaliated by costing Dunne in a triple threat match against Joe Hendry and Wes Lee for an NXT Championship match at NXT No Mercy on September 1, where Williams served as the special guest referee for the NXT Championship match between Hendry and Page. After the match, he was attacked by Dunne. Williams responded by releasing a diss track on Dunne which led to the two men brawling with each other throughout the September 3 episode of NXT. Williams and Dunne faced each other in a match later that night with the match ending in a double countout. The following week, Williams defeated Dunne in a Last Man Standing match to end their feud and to earn an NXT Championship match for the October 1 episode of NXT, where he defeated Page (with CM Punk as the special guest referee) to win his second NXT Championship. It was announced on the October 15 episode of NXT that Williams would defend his newly won NXT Championship in a Spin the Wheel, Make the Deal match at Halloween Havoc against Page, who won a triple threat number one contender's match. After spinning the wheel, it was revealed that the two would face off in a Devil's Playground match. At the event on October 27, Williams defeated Page to retain the title. After the match, Williams was attacked by Page and Ridge Holland before Bubba Ray Dudley came out to save him. On the following episode of NXT, Bubba Ray appeared in a segment with Williams, where Bubba Ray initially declined the latter's offer to be his tag team partner against Ridge and Page at NXT 2300. Later on however, after being saved by Williams from an attack by Holland and Page, Bubba Ray changed his mind and accepted Williams' offer. At NXT 2300 on November 6, Williams and Bubba Ray lost to Ridge and Page, with Ridge pinning Williams. After the match, Bubba Ray and Williams put Page through a table that was brought to the ring by D-Von Dudley. At NXT Deadline on December 7, Williams defeated Holland to retain the title and end their feud. On the December 17 episode of NXT, Williams' title match against Eddy Thorpe ended in controversial fashion as two referees counted two separate pins. After the show went off the air, NXT General Manager Ava confirmed that both Williams and Thorpe's shoulders were down, resulting in a double pinfall, thus Williams retained the title. At NXT New Year's Evil on January 7, 2025, Williams lost the title to Oba Femi in a triple threat match also involving Thorpe, ending his second reign at 98 days. He would then continue his feud with Thorpe, which culminated in a strap match at NXT Vengeance Day on February 15, where he lost. On the March 18 episode of NXT, Williams defeated Thorpe in an NXT Underground match to end their feud. After the match, Williams called out Femi to confront him. Immediately after, they were surrounded by DarkState (Dion Lennox, Cutler James, Saquon Shugars and Osiris Griffin) and Femi was taken out by Je'Von Evans. At Stand and Deliver on April 19, Williams failed to regain the title from Femi in a triple threat match also involving Evans.
On the April 22 episode of NXT, Williams began to tease a heel turn as his character shifted to become more selfish and entitled as he whined for another title opportunity from Femi. Afterwards, Williams would insult Joe Hendry following his surprise appearance and quick loss to Randy Orton at WrestleMania 41. Williams solidified his heel turn by helping DarkState win their match against Hendry and Hank Walker and Tank Ledger on the May 6 episode of NXT. At NXT Battleground on May 25, Williams defeated Hendry. On the June 3 episode of NXT, Williams defeated Mike Santana after interference from First Class (A.J. Francis and KC Navarro) and Josh Briggs on the June 25 episode of NXT, before being attacked by Hendry. Williams would attack Santana and Hendry during their tag team match against The High Ryze's Tyson Dupont and Tyriek Igwe on the July 8 episode of NXT. At NXT The Great American Bash, Williams would get laid out during a contract signing against Santana and Hendry, who would in turn get assaulted by DarkState. The three teamed up against the DarkState on July 15.
Williams next began feuding with NXT Champion Ricky Saints after he abandoned the latter during the Survivor Series-style match at NXT Showdown. Saints would defeat Williams in a match for the NXT Championship at NXT Halloween Havoc. Williams would lose to Saints again in a Last Man Standing match for the title on the November 11 episode of NXT. During week two of NXT Gold Rush on November 25, Williams was defeated by Myles Borne in a men's Iron Survivor Challenge qualifying match in what would be his final match for NXT.
On the December 26 episode of SmackDown, Williams declared himself to be a free agent. On the January 2, 2026 episode of SmackDown, Williams announced that he had been signed to the brand.