In January 2023, Dragon Lee was signed by WWE to begin on the NXT brand. On March 21, Dragon Lee was chosen as one of Wes Lee's opponent in a match for the NXT North American Championship at Stand & Deliver on April 1, where he would take part in a fatal five-way match, in a losing effort. On the April 4 episode of NXT, Lee would gain his first singles victory, over Nathan Frazer. At NXT Battleground in May, Lee would take on Noam Dar, for Dar's NXT Heritage Cup, where he would lose due to interference from Jakara Jackson and Lash Legend.
On the August 8 episode of NXT, Lee, with Rey Mysterio in his corner, failed to win the NXT North American Championship from Dominik Mysterio after interference from Rhea Ripley. On the September 25 episode of Raw, Lee again failed to defeat Dominik for the NXT North American Championship. The following night on NXT, Lee lost a fatal-four way match to earn a NXT North American Championship opportunity against Dominik at NXT No Mercy, which was won by Trick Williams. It was later announced that Lee would serve as the special guest referee for the title match at No Mercy. Lee then made an appearance in the crowd on the September 29 episode of SmackDown, where he got into an altercation with Austin Theory. Lee wrestled his official main roster debut match on the October 6 episode of SmackDown, where he defeated Theory in a singles match. He was then quietly moved to the SmackDown brand.
On the November 24 episode of SmackDown, Lee saved Carlito from being assaulted by Santos Escobar, who had turned heel and left the LWO two weeks before. Due to Carlito's injury, he was not able to take part in the match against Escobar at Survivor Series: WarGames, which then allowed SmackDown General Manager Nick Aldis to replace Carlito with Lee, but Lee would go on to lose the match on November 25. On the December 5 episode of NXT, Lee was revealed as Wes Lee's replacement to face Dominik Mysterio for the NXT North American Championship at Deadline. On the December 8 episode of SmackDown, Lee lost to Escobar in the first round of a United States Championship number one contender's tournament. The next night at NXT Deadline, Lee defeated Dominik to win the NXT North American Championship, his first title in WWE. On the December 12 episode of NXT, Lee successfully defended the North American Championship in his first title defense against Tyler Bate. The following week episode of NXT, Lee successfully defended the title in a triple threat match against Charlie Dempsey and Joe Coffey. On the January 9, 2024 episode of NXT, Lee successfully retained his title against Lexis King. After the match, Oba Femi cashed in his NXT Breakout Tournament contract and defeated Lee to win the title, ending Lee's reign at 31 days. On February 4 at Vengeance Day, Lee failed to win back the title from Femi in his rematch. On the April 3 premiere episode of WWE Speed, Lee was defeated by Ricochet in the tournament to crown the inaugural WWE Speed Champion.
Also in April, Lee would become an official member of the Latino World Order and was scheduled to team up with Rey Mysterio for a match against Santos Escobar and Dominik Mysterio on night one of WrestleMania XL. However, Lee was found attacked backstage, which rendered him unable to compete in the match. On the April 26 episode of SmackDown, Lee made his return from the attack and teamed up with Mysterio to defeat Legado del Fantasma (Angel and Humberto) in a tag team match. After the match, Escobar revealed that it was Carlito who had attacked Lee. Carlito then proceeded to attack both Lee and Mysterio after Escobar's revelation. On night two of the 2024 WWE Draft, the LWO were drafted to the Raw brand. In November, Lee joined the Speed Championship number one contender's tournament, defeating NXT's Tavion Heights and Akira Tozawa in the quarterfinals and semifinals respectively. He then received a bye to the championship match, where he defeated Speed Champion Andrade for the title on the November 20 episode of Speed.