Seo "Sol" Jin-sol joined NaJin e-mFire in May of 2015. He played for them in Challengers Korea Summer 2015 where NaJin made it to the playoffs but lost 3-1 in the first round to Incredible Miracle. Sol left NaJin in November.
He rejoined NaJin in December under a new name "SSol". The team renamed to e-mFire while they searched for a new organization. In February, that organization was found, and they renamed once again to Kongdoo Monster.
During the 2016 LCK Spring Season, Kongdoo Monster went 1-17 in sets, ending in last place. This forced them to play a relegation match against challenger team MVP, who defeated them 3-1 and relegating them to Challengers Korea 2016 Summer.