Park "Secret" Ki-sun joined the new Prime Clan early in 2015 as their support. They qualified for SBENU Champions Summer 2015 after going 1-1 in their group against Samsung Galaxy and Xenics during Champions Summer 2015 Promotion. Afterwards, Prime was sponsored by SBENU and renamed themselves to SBENU Sonicboom. Secret shares the starting support position with viviD. SBENU placed last in Champions Summer and were forced to play in the LCK 2016 Season Spring Promotion. SBENU played Ever and managed to win 3-1 to requalify for the LCK.
SBENU played in the 2015 LoL KeSPA Cup where they lost 2-1 in the quarterfinals to SK Telecom T1.
During the 2016 LCK Spring Season, SBENU Sonicboom went 2-16 in sets, finishing in ninth place, forcing them to play relegations matches for their spot in the summer split. SBENU chose ESC Ever as their relegations opponent, but were defeated 3-0, relegating them to Challengers Korea 2016 Summer.