On September 7, 2018, Blizzard Entertainment announced that OverActive Media (OAM) had purchased a slot for a Toronto-based franchise.

[10] The team failed to recreate the success they found in Stage 1, winning only three matches in their final four months of play.

[11] A 2–3 loss to the Fusion on August 4 officially eliminated Toronto from postseason contention,[12] and three days later, the team released head coach Bishop, leaving assistant coaches Optidox, Mobydik, and Barroi to lead the team in the final weeks of the regular season.

[10] Over the following off-season, the Defiant parted ways with the vast majority of their roster, aside from support player Park "RoKy" Joo-seong, Logix, and Mangachu.

The team advanced to the North America play-in tournament, where they lost to the Los Angeles Gladiators by a score of 2–3.

[19] In late May 2021, the Defiant had a COVID-19 outbreak in its facility, sidelining both of their damage players, Logix and Jeong "Heesu" Hee-su.

[20] In the final week of the regular season, the Defiant defeated the Paris Eternal to secure a spot in the West play-in tournament.

[6] All-Star Game selections On February 14, 2019, Overactive Media partnered with Mirage Sport Électronique to launch Toronto Defiant's official academy team in Montreal to compete in Overwatch Contenders.

"We are really excited about partnering with Yannick and his team to launch the first pro esports franchise in Quebec," Overholt said in an interview.

"Today is about continuing our commitment to growing esports nationwide, and expanding our Toronto Defiant fanbase in Quebec and across Eastern Canada.