Hjelte started playing
Super Smash Bros. in 2009, when he was introduced to
Super Smash Bros. Melee. He initially started as a
Yoshi and
Falco player before switching to Fox. Leffen feels that he made the gradual switch from Falco to Fox because he views Falco as requiring more discipline and Fox being more suited to his play style. He placed 9th in the
Swedish national tournament B.E.A.S.T 2 within his first year of playing
Melee. Throughout 2014 Leffen began placing highly in tournaments and defeating the top five
Melee players regularly. Prior to
EVO 2014, Joe Cribari of
Nintendo Enthusiast listed Leffen among the three "underdogs" with the greatest chance to win the tournament. He finished 9th at EVO 2014. In VGBootCamp's
Apex 2015 Salty Suite, Hjelte defeated Kashan "Chillin" Khan in a first-to-five set without dropping a single game, and gained the "rights" to use Fox's default color.
Mang0 subsequently challenged Hjelte to a 1,000 money match if they were to face-off in the Apex Singles bracket. Hjelte would in turn beat Mango when they played in Winners' Semifinals. On March 9, 2015, Hjelte was signed by
Team SoloMid as its first player on their
Super Smash Bros. division, as well as their first fighting game player. At CEO 2015 in
Orlando, Florida, Leffen won his first American major, defeating Armada. He placed 5th at
EVO 2015 later that year, despite being a favorite to win. He was upset by Panda Global's
Plup who played
Samus.
Melee it on Me ranked Leffen as the 2nd best player in the world in their summer 2015 mid-season rankings. Leffen was barred from entering the United States just before The Big House 5 tournament because he was travelling on an
Electronic System for Travel Authorization (ESTA) and employed by US-based
Team SoloMid. On February 16, 2016, Leffen became sponsored by
Red Bull as an official Red Bull Athlete. As of 2018, he was no longer with Red Bull.
Visa issues and EVO 2018 On April 29, 2016, Leffen announced that his
Form I-129 petition to obtain a
visa had been denied by
United States Citizenship and Immigration Services. On 4 May 2016 it was initially announced that
Team SoloMid was able to secure a P1 Visa for Leffen so he can be able to attend US-based tournaments throughout July which includes
EVO 2016 and that TSM was working on extending this visa for the long term. However, on July 14 Leffen announced that he had run into additional delays in the visa approval process and would miss EVO. Finally, on October 3, Leffen's visa was approved, allowing him to compete in US-based tournaments again, in time for The Big House 6. In August 2018, Leffen won
Evo 2018, defeating Armada 3–0 in grand finals to claim the trophy.
Other games Hjelte has competed in fighting games including
Dragon Ball FighterZ,
Ultra Street Fighter IV,
Ultimate Marvel vs. Capcom 3, and
The King of Fighters XIII. According to the PGRZ, Hjelte is considered the 28th best Dragon Ball FighterZ player of all time. In an interview with EventHubs prior to Apex 2015, he suggested he might play
Guilty Gear Xrd on his
Twitch stream after
Apex 2015 concluded. As of the release of
Guilty Gear Strive, Hjelte has been hosting online tournaments for the game, hosting the title's first major, the Big LEVO. At
Evo 2022, Leffen placed 3rd out of 2,161 entrants in Guilty Gear Strive, making this the first time that a player has made Top 8 at EVO in both a Smash title as well as a traditional fighting game. The following year, Leffen would take 1st out of 2,474 entrants in the same game at
Evo 2023, becoming the first person to hold victories in both Smash and a traditional fighting game in EVO. ==Personal life==