Prior to the 2015 LoL KeSPA Cup, Ever brought in former KT Rolster jungler Ares (additionally, support TML renamed to Key). They upset Samsung Galaxy and Rebels Anarchy in the first two rounds. Expected to fall 2-0 to recent World Champions SK Telecom, who tried out substitute Scout onstage for the first time in game 1, Ever shocked audiences by not only winning that first game but sweeping the team 2-0, even with Faker playing the second game. Against CJ Entus in the finals, Ever once again swept the series, this time 3-0, and qualified for IEM Cologne as Korea's only seed to the event. Ever continued their strong performance at IEM, defeating H2k 2-1 and then Qiao Gu 3-2 to win the tournament. Their victory marked the first time since the inception of the League Championship Series in 2013 that a team unable to qualify for their national premier league won a major international event. LokeN delivered stunning performances throughout the tournament, especially on Tristana, and he and Key gained recognition as a world-class botlane. However, after the tournament, mid laner Athena departed the team, and so their IEM Championship lineup was unable to play together again.
At the time of competing at IEM Katowice (which they had an invitation to due to winning IEM Cologne), Ever were in second place in Challengers, after losing a series 0-2 to MVP. Despite a round-one surprise upset win over Team SoloMid, Ever lost to Royal Never Give Up and then a rematch series against TSM to be eliminated before the playoff bracket.
After coming back to Korea, ESC Ever continued to perform well in the Challengers Korea 2016 Spring Season, finishing second place in the regular season with 27 pts. After beating Ever8 Winners 3-1, they beat MVP 3-2 to win the season and earn a spot in the 2016 LCK Summer Promotion. Then, they beat SBENU Sonicboom 3-0 to earn a spot in the 2016 LCK Summer Season.
During the 2016 LCK Summer Season, ESC Ever went 5-13 in total sets, with one notable upset victory over SK Telecom T1. However, they still finished the split in ninth place, leading them to participate in the 2017 LCK Spring Promotion tournament. In the first round, they beat SBENU Korea 2-1 before falling to Kongdoo Monster 3-1. In the deciding loser's match, ESC Ever swept CJ Entus to earn their spot back in the LCK.