Chen debuted for WWE on September 22, 2021, on the NXT brand, winning his first match. Chen debuted on the 205 Live brand on October 1. After returning to newly renamed NXT 2.0 in 2022, Chen was attacked by Duke Hudson. Chen would feud with Hudson during the first months of 2022, ultimately losing in their singles match. Chen made his debut on NXT Level Up against Javier Bernal in March 2022. Chen continued on NXT Level Up, participating in a feud with Bodhi Hayward, where he would win the first match in March, and lose the second in April. Over the course of April and May, Chen would lose six matches in a row, to various wrestlers including Xyon Quinn and Sanga. In an effort to win, Chen would form a tag team with Javier Bernal in May, however the duo would lose all three of their tag matches, extending his losing streak to nine in a row. On the July 8 edition of NXT Level Up, he defeated Myles Borne, ending his losing streak . However, Chen lost to the debuting Axiom the following week. Despite this, on the August 5 edition of NXT Level Up, Chen would team up with Guru Raaj against Bryson Montana and Damaris Griffin, where he would pick up his first tag team victory in NXT. On the November 29 edition of NXT, Dante Chen would lose to Dijak.
On March 13, 2023, Chen made his debut on WWE Main Event, where he would be defeated by Cedric Alexander. Throughout 2023, Chen would serve as the "gatekeeper" of NXT Level Up, facing the majority of debuting talent on the show, including the likes of Drew Gulak, Damon Kemp, Charlie Dempsey, Scrypts and many others while also teaming with Boa several times. On October 24 at NXT Halloween Havoc night one, Chen was defeated by Lexis King in King's first televised WWE match. Following the loss, Chen began appearing in vignettes alongside Boa, and on the November 7 episode of NXT, he began to sport the same face paint as the latter, confirming their alliance in the process. On February 16, Chen made his main roster debut, losing to Bron Breakker on SmackDown. Chen returned to NXT on the May 21 episode, defeating Lexis King thanks to his new manager, Robert Stone.