MakNooN first played for a team called Extreme Dive Gaming in 2011 and 2012, before joining NaJin e-mFire as their toplaner in February 2012. Along with HooN, MOKUZA, viNylCat, and Hiro, MakNooN played in the Champions Spring 2012. The team made it out of the group stage but lost in the quarterfinals of the playoffs to MiG Frost. When NaJin split into two sister teams in June 2012, MakNooN joined NaJin Sword to play in Champions Summer; this time, his team finished in third place, beating Azubu Blaze in the third-place match.
In June 2012, MakNooN was invited to play at the Riot World Invitational, along with Snoopeh, Misaya, MiSTakE, and Elementz. That team played against a team of Rioters in a best-of-three show match. The World team won 2-0.
At the regional finals, NaJin Sword had the fourth seed but were able to beat Incredible Miracle, Xenics Storm, and Azubu Blaze to qualify for the Season 2 World Championship. MakNooN was one of the fan favorite players, known for his extremely aggressive playstyle and tendency to tower dive. NaJin Sword advanced to the bracket stage but then lost to eventual tournament winners Taipei Assassins in the quarterfinals.
Najin Sword won Champions Winter 2012-2013, and MakNooN was named MVP of the tournament, but after a quarterfinal elimination in Champions Spring, MakNooN left the team in May 2013 and joined KT Rolster A, later renamed to KT Rolster Arrows. He was replaced on Sword by Expession. KT A did not qualify for Champions Summer.
In October 2013, MakNooN left the KT Arrows to join CJ Entus Frost, switching from toplane to midlane and replacing Rapidstar. With CJ Frost, he placed second at IEM Singapore but only advanced to the quarterfinals of Champions Winter. On January 28th, MakNooN left CJ Frost, along with Cpt Jack, Helios, and Ganked by Mom.
MakNooN briefly coached paiN Gaming from May to June 2014.
On October 23rd, 2014 it was officially announced that MakNooN would be the toplaner for Team Fusion, a team formed to play in the North American Expansion tournament. The team qualified for the tournament via the ranked 5's ladder with substitute player Bee Sin filling in for MakNooN before he arrived in the United States from Korea.
Team Fusion won their first-round match against Team Confusion due to a forfeit from Confusion, and then defeated Enemy eSports 2-0 in the second round, with MakNooN famously playing Poppy in both games and drawing pressure to his lane. In the offline tournament, Team Fusion narrowly beat Final Five 3-2 after losing the first two games. They then lost to Curse Academy 3-1 and were knocked down to the loser's bracket to face Team Coast. This time, Fusion got ahead 2-0 but then ultimately lost the series and did not qualify for the LCS.
On January 6th, it was announced that MakNooN had been released from the Team Fusion roster.