Rezar

Akam (left) and Rezar (right) with Paul Ellering (middle), as the NXT Tag Team Champions in February 2017

Selmani got invited for a tryout in Dubai, and it was William Regal’s choice to get him to sign a contract for WWE. In May 2015, it was reported that Selmani had signed a contract with WWE and would begin training to become a professional wrestler at the WWE Performance Center.[8] In October 2015, WWE confirmed that Selmani was a WWE developmental recruit already training at the Performance Center.[9] He made his in-ring debut at a NXT house show in Venice, Florida on 30 January 2016, losing to Josh Woods.[2] By February 2016, Selmani had formed a tag team with Sunny Dhinsa,[10] and they became known as The Authors of Pain by April 2016.[11]

Selmani and Dhinsa made their televised NXT debuts on 8 June 2016 at NXT TakeOver: The End;[12] following the NXT Tag Team Championship match, they attacked champions American Alpha (Chad Gable and Jason Jordan) before leaving backstage with Paul Ellering.[13] On 15 June episode of NXT, the Authors of Pain won their first televised match and were managed by Ellering.[14] On the 24 August episode of NXT Selmani's ring name was revealed to be Rezar,[15] while Dhinsa was billed as Akam.[16] The duo won the 2016 Dusty Rhodes Tag Team Classic, defeating TM61 in the tournament final at NXT TakeOver: Toronto. At NXT TakeOver: San Antonio, the Authors of Pain defeated #DIY to win the NXT Tag Team Championship. They retained the title at NXT TakeOver: Orlando by defeating #DIY and The Revival in a Triple Threat Tag Team Elimination match by eliminating both teams. At NXT TakeOver: Chicago, the duo participated in the first NXT Takeover main event for the NXT Tag Team Championship by defeating #DIY in a ladder match to retain the title. At NXT TakeOver: Brooklyn III, the Authors of Pain lost the titles to SAnitY. at NXT TakeOver: WarGames, Authors of Pain and Roderick Strong competed in a 3 team WarGames match which was won by The Undisputed Era. On 20 December episode of NXT, Authors of Pain lost the NXT Tag Team Championship to Bobby Fish and Kyle O'Reilly. At NXT TakeOver: Philadelphia, Authors of Pain got a rematch but were unsuccessful. At NXT TakeOver: New Orleans, Authors of Pain competed in a Triple threat tag team match for the NXT Tag Team Championship and Dusty Rhodes Tag Team Classic trophy which was won by The Undisputed Era (Adam Cole and Kyle O'Reilly).

On 9 April episode of Raw, The Authors of Pain, along with Ellering, made their main roster debut, defeating Heath Slater and Rhyno. After the match, Akam and Rezar ended their partnership with Ellering by pushing him away and leaving him ringside as they returned backstage.[17] On 3 September episode of Raw, The Authors of Pain, now under the shortened name of "AOP", were accompanied to the ring by the 205 Live General Manager, Drake Maverick, who announced himself as their new manager.[18]

On 5 November episode of Raw, The Authors of Pain defeated Seth Rollins in a handicap match to win the Raw Tag Team Championship for the first time. They went on to defeat SmackDown's Tag Team Champions Cesaro and Sheamus in an interbrand Champion vs Champion match at Survivor Series. They lost the titles to Bobby Roode and Chad Gable on 10 December episode of Raw. In January 2019 Akam suffered an undisclosed leg injury that reportedly would keep him out for “at least a few months”. He and Akam returned to action at Super ShowDown on 7 June 2019.[19]

In September 2019, AOP began appearing in vignettes, warning of their return. During the 2019 WWE Draft in October, AOP went undrafted, becoming free agents and able to choose which brand to sign with. Three days after the draft's conclusion, AOP signed with Raw, remaining on the brand.[20] Rezar stared to show with Akam as Seth Rollins' disciples. In March 2020, it was reported that Rezar suffered a bicep injury and the injury would sideline him for six to eight months.[21] On 4 September 2020, AOP were released from their WWE contracts.[22][23]

In May 2022, Gzim Selmani and Sunny Dhinsa, now known as Legion of Pain, have announced the launch of their professional wrestling promotion, Wrestling Entertainment Series (WES).[24]

According to a report from Sean Ross Sapp of Fightful on August 30, 2023, the Authors of Pain had been re-signed with the WWE in 2022 prior to the return of Vince McMahon as chairman in January 2023 and they were on the internal travel list as of May of 2023.[25][26]