In November 2011, Lefort wrestled a single appearance for WWE on SmackDown as a local wrestler who, along with Andy Baker and Zak Zodiac, lost a handicap match against Big Show.
In August 2012, WWE signed Lefort to a contract. In WWE's developmental territory NXT Wrestling, he made his television debut on the May 29, 2013 episode, where he (as a rich Frenchman) managed the tag team of Garrett Dylan and Scott Dawson (two Southerners) in a win over Travis Tyler and Baron Corbin. After Dylan and Dawson lost a number one contendership match for the NXT Tag Team Championship to Corey Graves and Kassius Ohno on the June 26 episode of NXT, Dylan was released from WWE in August 2013, but Lefort continued to manage Dawson. He also began managing Alexander Rusev. He made his NXT in-ring debut teaming with Rusev in a win over Enzo Amore and Colin Cassady. During the match, Rusev turned on Lefort and sided with the debuting Lana. Lefort went on to lose to Rusev in a singles match. With Dawson injured, Lefort began to wrestle in singles competition, losing to Mason Ryan in early 2014.
Lefort formed a new tag team with Marcus Louis as "The Legionnaires", playing up a gimmick based on their French heritage. They wrestled their first televised match on the May 8 NXT, losing to a debuting Kalisto and El Local, then on December 19, in a triple threat tag team elimination match against Colin Cassady and Angelo Dawkins, and The Ascension (Konnor and Viktor), which was won by Cassady and Dawkins. On the May 8 NXT, The Legionnaires began a feud with Enzo Amore and Colin Cassady. Lefort faced Enzo Amore in a hair versus hair match at NXT TakeOver: Fatal 4-Way and was defeated, but did not adhere to the stipulation post-match, and instead ran away, leaving his partner Louis to be shaved bald instead. In the following weeks, Lefort tried to get revenge on Enzo Amore and Colin Cassady. On the October 16 episode of NXT, Louis finally snapped and turned on Lefort and attacked him during a tag match.
On June 24, 2015, after an eight month hiatus from NXT programming, Lefort returned to team with Jason Jordan in a losing effort to Enzo Amore and Colin Cassady. In November 2015, Lefort began managing Billie Kay at NXT house shows. On February 5, 2016, it was announced that Lefort had been released from his WWE contract.