Former professional esports player Lauri “Cyanide” Happonen, who made history by winning the inaugural League of Legends World Championship with Fnatic in 2011, has died at the age of 31.
The Finnish gaming champion died July 31, although his death was not publicly confirmed until Monday, October 26, according to Finnish newspaper Ilta-Sanomat.
Finland’s Digital and Population Data Services Agency confirmed his death to the publication.
The circumstances surrounding Happonen’s passing have not been disclosed, and no official cause of death has been announced.
Known professionally as Cyanide, Happonen was one of the earliest stars of competitive League of Legends, helping establish the game as a major international esports competition.
He was just 16 when Fnatic captured the first League of Legends World Championship in 2011, making him the youngest world champion in the game’s history.
His victory came during the formative years of professional League of Legends, before the competition developed into the global esports spectacle it would later become.
Happonen played the jungle position for Fnatic, helping the organization build its reputation as a dominant force in European competition.
Following the team’s championship victory, he became part of Fnatic’s celebrated roster alongside Paul “sOAZ” Boyer, Enrique “xPeke” Cedeño Martínez and Bora “YellOwStaR” Kim.
The lineup went on to secure three European League of Legends Championship Series titles between 2013 and 2014.
Their success helped cement Fnatic’s position among the leading organizations in competitive gaming.
Happonen eventually stepped away from top-tier competition before officially retiring at the end of 2022.
Despite his retirement, he remained connected to the community that had followed his career for more than a decade.
In a particularly poignant detail, Happonen participated in an EU LCS Classic Showmatch during Karmine Corp’s Roadtrip event in France on July 25, 2026.
The exhibition reunited players associated with the earlier years of professional League of Legends.
It took place just six days before his reported death.
Former teammate YellOwStaR, who saw Happonen at the event, shared an emotional tribute following Monday’s announcement.
“Lauri was so much more than a teammate,” he wrote.
“We shared our everyday lives for over two and a half years, and he became so much more than just someone I played alongside.”
YellOwStaR described Happonen as one of the most genuine people he had encountered during his career.
“He was one of the kindest, most genuine souls I’ve ever had the privilege of knowing,” he continued.
“We saw each other again at the showmatch in July, and he was still full of dreams, plans, and projects for the future.”
The former teammate concluded by thanking Happonen for their years together.
“You will be deeply missed, brother. Thank you for the memories, the time we shared, and for the person you were. Rest in peace, my bro.”
Others throughout the esports industry also paid tribute to the former champion, as Sheepes Sports reported.
Fnatic head coach Fabian “GrabbZ” Lohmann credited Happonen with influencing the development of competitive League of Legends.
“Undoubtedly helped shape the early scene to what it is today,” Lohmann wrote.
“Many of us became fans of the game and competitive scene due to players like him.”
Fnatic co-streamer JordiLMK similarly credited Cyanide with inspiring his interest in professional gaming.
“I’m going to miss you, Cyanide. Without you, I would never have started watching LoL back in 2014,” he wrote.
Spanish League of Legends personality Antonio “Th3Antonio” Espinosa also remembered watching Happonen’s performances alongside xPeke during Fnatic’s early success.
Happonen’s death marks another loss for the organization’s original world championship roster.
His former teammate Maciej “Shushei” Ratuszniak died in April 2025 at age 36 following a battle with cancer.
With Happonen’s passing, two members of Fnatic’s historic 2011 championship team have now died.
His legacy remains closely tied to the earliest years of professional League of Legends and the championship victory that helped shape the future of competitive gaming.
