On November 3rd 2014, it was announced that Emperor was leaving the CJ organization and not re-signing for the 2015 season. In December, he joined Keyd Stars as their starting AD carry, replacing Rafes. They placed second in the CBLOL 2015 Summer Playoffs after losing 3-0 to INTZ e-Sports. Emperor left the team shortly after the tournament. Emperor joined Team Dragon Knights on May 18th, 2015 after they qualified for the LCS; however, he and mid laner Ninja both missed the first four-and-a-half weeks of play due to visa issues, and the team used AD carry substitute LattmaN and mid lane substitutes Bischu and mancloud instead. When Emperor and Ninja finally were able to play, the team found their first victory of the split, defeating then first-place Team Dignitas. Despite that initial success, Team Dragon Knights were only able to secure two more victories over the next four weeks, and they finished in last place with a 3-15 record, one game behind Enemy. As a result, they were automatically relegated to the 2016 NA Challenger Series Spring Season.
G2 Esports quickly rose to prominence and recognition in the LCS, consistently tied for first place after each week, sometimes with H2k and sometimes also with Vitality, until the end of the split when they held first place with sole possession. With a quarterfinal bye, the playoffs also saw them strong, as they defeated both Fnatic and Origen 3-1 to win the season and secure an invitation to the Mid-Season Invitational.
Going into MSI, G2 Esports were seen as a favorite not to win, but to come in second place to the Korean representatives SK Telecom T1. However, the team lost their first four games of the round robin and ultimately finished in fifth place, ahead of only SuperMassive eSports, and out of playoff contention - importantly, this placement meant that Europe would forfeit their Pool 1 seed at Worlds. In a statement published partway through the second day of play, G2 stated that their players had taken vacation time after a "rigorous Spring Split." Emperor later stated that there had been an internal conflict within the team one day prior to the start of the event.