In December 2006, Konnor appeared on an episode of ECW as one of Paul Heyman's personal enforcers alongside Doug Basham.
During mid-2007, Konnor would appear in dark matches prior to Raw and SmackDown against Sylvan Grenier, Chuck Palumbo, Super Crazy, Cody Rhodes and D'Lo Brown.
On November 30, 2010, during the season finale of season three of NXT, it was announced that Konnor, under the name Conor O'Brian, would be appearing on season four, with Alberto Del Rio as his mentor. He made his in-ring debut on NXT the following week, teaming with Del Rio to defeat rookie Derrick Bateman and Bateman's mentor Daniel Bryan. O'Brian won his first challenge on the January 4, 2011 episode of NXT, when he won the 'Battle of the Mic Challenge' to earn four immunity points. Two weeks later, on January 18, O'Brian was the second contestant eliminated from NXT. Earlier that night, O'Brian competed in a match against Ricardo Rodriguez in a losing effort.
In March 2011, O'Brian was selected as one of the six former NXT contestants to return to the show in its fifth season, NXT Redemption. During this season, O'Brian was mentored by Vladimir Kozlov. He was later eliminated from competition on the June 28, 2011 episode of NXT, and would later be joined, and eventually replaced, by a returning Derrick Bateman and Daniel Bryan.
With the conclusion of NXT Redemption, WWE rebranded NXT into its developmental territory. O'Brian and Kenneth Cameron, as The Ascension, debuted on the June 20 episode of the rebooted NXT taped at Full Sail University, where they defeated Mike Dalton and CJ Parker. The Ascension then started a feud with The Usos, defeating them on the September 5 NXT, and also scored a win over Justin Gabriel and Tyson Kidd on the October 3 NXT. Two weeks later, the Ascension teamed up with Kassius Ohno to defeat Richie Steamboat and the Usos. The Ascension disbanded on November 30, 2012 when Cameron was released from WWE.
O'Brian retained his character while using "The Ascension" as his nickname as he started to feud with Big E Langston for the NXT Championship. O'Brian first faced Langston in a non-title match, which ended in a double disqualification. O'Brian then faced Corey Graves in a number one contender match which had no winner when the Shield attacked both men to make a statement. The next week, O'Brian defeated Graves and Bo Dallas to become the number one contender. The feud ended after O'Brian was defeated in a title match on the April 4 episode of NXT. On the May 29 NXT, O'Brian competed in an 18-man number one contender battle royal and was eliminated by Corey Graves and Kassius Ohno. To reform the Ascension tag team, Rick Victor allied himself with O'Brian as they went chased the NXT Tag Team Championships held by Adrian Neville and Corey Graves. On November 10, 2013 O'Brian's name was tweaked and shortened to "Konnor". On February 27, 2014 at NXT Arrival, he and Viktor successfully defended the NXT Tag Team Championships against Too Cool, repeating the feat on May 29, 2014 at NXT TakeOver against the team of El Local and Kalisto.
Konnor, alongside Viktor, made his main roster debut on the September 9, 2014 episode of Main Event, with the duo defeating Los Matadores (Diego and Fernando) in a tag-team match to promote their NXT tag title defense against The Lucha Dragons (Kalisto and Sin Cara) at the NXT TakeOver: Fatal 4-Way event. On the December 12 episode of SmackDown, vignettes began to air promoting The Ascension's call-up to the main roster. The Ascension made their debut on the December 29 episode of Raw, quickly defeating The Miz and Damien Mizdow. The Ascension would continue to squash local athletes three weeks in a row on Main Event while indirectly criticizing of The Road Warriors. Their first major victory as part of the main roster was a win over The New Age Outlaws at the Royal Rumble. The Ascension suffered their first pinfall loss on the main roster on February 23 episode of Raw, losing to The Prime Time Players (Darren Young and Titus O'Neil). At WrestleMania 31, The Ascension made their WrestleMania debut in the André the Giant Memorial Battle Royal where both failed to win the match. On the May 11 episode of Raw, during a match between Curtis Axel and Macho Mandow, in the guise of Randy Savage, The Ascension attacked Axel and Mandow. It was then announced that the Ascension would face Axel and Mandow on the Payback pre-show, where they won the match. It was announced the Ascension would par take in a six team elimination chamber match for the WWE Tag Team Championship. At Elimination Chamber on May 31, he and Viktor eliminated the Los Matadores and The Lucha Dragons until they were eliminated by The Prime Time Players, ultimately losing the match.
On the September 3 episode of SmackDown, The Ascension aligned themselves with Stardust by attacking Neville before their match, and thus forming a group known as "The Cosmic Wasteland". At Night of Champions, The Cosmic Wasteland defeated Neville and the Lucha Dragons on the pre-show. On the Survivor Series kickoff, The Cosmic Wasteland, The Miz, and Bo Dallas were defeated by The Dudley Boyz (Bubba Ray Dudley and D-Von Dudley), Neville, Goldust and Titus O'Neil, in a traditional Survivor Series elimination tag team match. On the Royal Rumble kickoff, The Ascension lost a Fatal 4-Way tag team match to qualify for the Royal Rumble match. At WrestleMania 32, Konnor competed in the André the Giant Memorial Battle Royal but failed to win the match. On April 16, 2016, Konnor was suspended for 60 days for his second violation of the Wellness Program. On the June 24 episode of Superstars, Konnor returned from suspension when The Ascension faced the Golden Truth (Goldust and R-Truth) in a losing effort.
On July 19 at the 2016 WWE draft, The Ascension were drafted to SmackDown, making their debut on the July 26 episode in a WWE World Championship No. 1 Contender's Six-Pack Qualifying Battle Royal, which was won by Apollo Crews. On the SummerSlam kickoff, The Ascension competed in a 12-man tag team match where their team lost. They then entered the SmackDown Tag Team Championship tournament, where they were eliminated in the first round by The Usos. On the September 27 episode of SmackDown Live, The Ascension picked up their first win on the brand, when The Ascension and The Usos defeated Heath Slater, Rhyno and American Alpha (Chad Gable and Jason Jordan) in an eight-man tag team match. At 2017 Elimination Chamber, The Ascension competed in a tag team turmoil match for the SmackDown Tag Team Championship where they were the final team eliminated. Konnor, alongside Viktor, would later enter the André the Giant Memorial Battle Royal at WrestleMania 33, but both men were eliminated from the match. At Money in the Bank, The Ascension lost to Breezango after they claimed responsibility for a vandal attack in their office. On the June 27 episode of SmackDown Live, The Ascension was interrogated by Breezango on "Fashion Vice", admitting that they didn't commit the crime and only took responsibility, because they wanted a match at the PPV. In September, the duo turned face when they started trying to befriend Breezango during the latters' 'Fashion Files' segments. On the January 9 episode of SmackDown Live, The Ascension a loss to The Bludgeon Brothers (Harper and Rowan), for a while the duo would only appear as supporting characters in Breezango's Fashion Files skits. The duo were participants in the André the Giant Memorial Battle Royal at WrestleMania 34, with Konnor being the first of the duo to be eliminated.
During the 2018 Superstar Shake-up, The Ascension were traded to Raw. On the April 23 episode of Raw, The Ascension, once again as heels, facing against the team of Matt Hardy and Bray Wyatt in a losing effort. At the Greatest Royal Rumble event, Konnor entered at number 19 but was eliminated by Elias. On the September 24 episode of Raw, he got a victory over Chad Gable in singles competition. On the October 1 episode of Raw, he defeated Bobby Roode.
At WrestleMania 35, Konnor competed in the Andre the Giant Memorial Battle Royal, but was unsuccessful. On December 8, 2019, after not appearing on television for the latter half of the year, Konnor and Viktor were released from their contracts.