On January 22, 2016, WWE announced that Aries would be joining NXT. On the March 2 episode of NXT, Aries made his debut as a fan favorite, being introduced by NXT General Manager William Regal before being attacked by Baron Corbin on his way to the ring. A match was booked between the two at NXT TakeOver: Dallas on April 1, where Aries defeated Corbin. On the May 18 episode of NXT, Aries teamed up with Shinsuke Nakamura to defeat the team of Blake and Murphy. On the May 25 episode of NXT, Aries declared his intention to become the next NXT Champion, which prompted a response from Nakamura, and NXT General Manager William Regal then scheduled a match between the two at NXT TakeOver: The End on June 8, which Nakamura won. On the June 22 episode of NXT, Aries came out to seemingly thank No Way José for reminding him that wrestling was about having fun, only to attack him after an impromptu dance party, turning heel in the process. Aries defeated No Way José by submission at NXT TakeOver: Brooklyn II on August 20. Aries entered the second Dusty Rhodes Tag Team Classic tournament, teaming with Roderick Strong, but the pair dropped out of the tournament after advancing through the first round after Aries suffered an injury.
On October 27, Aries suffered a large orbital socket injury during a live event at Fresno, California, in a match against Shinsuke Nakamura and was expected to be out of action until early 2017. It was revealed in November 2016 that permanent titanium plates were inserted to repair the injury.
On December 18, at Roadblock: End of the Line, Aries made his WWE pay-per-view debut alongside Michael Cole and Corey Graves, calling the triple threat match between Rich Swann, TJ Perkins and The Brian Kendrick. The following night on Raw, Aries provided commentary during the cruiserweight match. Aries also provided commentary alongside Mauro Ranallo and Corey Graves on 205 Live, as well as on Main Event.
On the March 6, 2017 episode of Raw, Aries turned face by attacking WWE Cruiserweight Champion Neville while taking an interview with him. On March 7, he made his 205 Live in-ring debut, defeating Tony Nese. On March 13, Aries defeated Ariya Daivari on his Raw in-ring debut. On the March 14 episode of 205 Live, Aries defeated TJ Perkins, Akira Tozawa, The Brian Kendrick and Tony Nese in a Fatal 5-Way elimination match to become the number one contender for the WWE Cruiserweight Championship at WrestleMania 33, last eliminating Kendrick to win. However, Aries lost to Neville during the pre-show in the opening match. On the April 4 episode of 205 Live, Aries defeated Jack Gallagher, TJ Perkins and Mustafa Ali in a fatal four-way match to earn a rematch against Neville at Payback, which he won by disqualification. Aries again failed to win the Cruiserweight Championship after he was defeated by Neville at Extreme Rules in a submission match.
On July 7, 2017, Aries was released from his WWE contract.