[8] In February 2015, Monster Mafia debuted for Pro Wrestling Guerilla (PWG), facing The Young Bucks in their first match.

[7][10] Impact Wrestling subsequently hyped Alexander's debut with an online documentary made by Toronto-based filmmaker Glen Matthews.

[11] Alexander reformed with Ethan Page under the name The North, as they defeated El Reverso and Sheldon Jean on the April 12 episode of Impact!

On the June 14 episode of Impact!, North defeated Rob Van Dam and Sabu to earn a title shot against The Latin American Xchange (Santana and Ortiz) for the World Tag Team Championship at the Bash at the Brewery event on July 5.

[15] The North unsuccessfully challenged Motor City Machine Guns in a rematch for the World Tag Team Championship at Emergence but regained the titles at Bound for Glory, before lost it a few weeks later to The Good Brothers at Turning Point.

[25] On June 3, Alexander defended the title against TJP in Impact's first-ever 60-minute Iron man match, winning 2–1 in sudden death overtime.

[26] At Slammiversary on July 17, Alexander successfully retained his X Division Championship in an Ultimate X match against Austin, Chris Bey, Petey Williams, Rohit Raju, and Trey Miguel.

[27] Alexander then retained his title against Black Taurus at Homecoming,[28] against Jake Something at Emergence,[29] and against Chris Sabin at Victory Road.

[39][40] At Sacrifice on March 5, Alexander made his return, attacking Impact World Champion Moose after his match against Heath.

[47] On July 31, at Ric Flair's Last Match event, Alexander defended the title against Major League Wrestling (MLW) talent Jacob Fatu, but it ended in a no contest due to interference from Brian Myers, Matt Cardona and Mark Sterling.

[50] At Bound for Glory, Alexander made another successful title defense against Edwards, before being confronted by Call Your Shot Gauntlet winner Bully Ray.

[52] On the December 8 episode of Impact!, Alexander fought Mike Bailey for nearly an hour to successfully defend his title, garnering positive reviews from critics.

[59][60] Nine days later, at Hard To Kill, Alexander defeated Call Your Shot Gauntlet winner Bully Ray in a Full Metal Mayhem match to retain the title.

[63] On March 24, it was announced that Alexander has relinquished the title due to him suffering a triceps tear, ending his second and record-setting reign at 335 days,[64][65] with the segment airing on the April 9 tapings of Impact.

[68] He returned to action at Emergence, teaming up with Time Machine (Chris Sabin, Alex Shelley and Kushida) in an eight-man tag team match against Brian Myers, Lio Rush, Bully Ray, and Moose, which they lost when Steve Maclin, who also made his return from injury, interfered in the match by attacking Alexander.

[79] At Slammiversary, Alexander competed in a 6-man elimination match, for the TNA World Championship that included Joe Hendry, Steve Maclin, Nic Nemeth, Frankie Kazarian, and reigning champion, Moose.

After failing to win the TNA World Championship from Nic Nemeth in an Iron Man match at Emergence, Alexander lost to Hendry via submission at Victory Road.

On the October 10 episode of Impact!, Alexander formed a new stable known as The Northern Armory, with fellow stablemates Judas Icarus and Travis Williams.

On December 13, at Final Resolution, Josh competed in a four-way match to determine the number one contender to the TNA World Championship that included Joe Hendry, Steve Maclin and Mike Santana, in a losing effort.

[81] Alexander made his debut for New Japan Pro-Wrestling on the June 18, 2021, episode of NJPW Strong and defeated Alex Coughlin.

[83] At Destruction In Ryōgoku, Alexander and the Motor City Machine Guns (Alex Shelley and Chris Sabin) unsuccessfully challenged Kazuchika Okada, Hiroshi Tanahashi, and Tomohiro Ishii for the NEVER Openweight 6-Man Tag Team Championship.