Jang "MaRin" Gyeong-Hwan first joined the competitive scene when SK Telecom T1 1 was formed around him on October 12th, 2013. The team renamed to SK Telecom T1 S a few months later. They qualified for PANDORA.TV Champions Winter 2013-2014 where they failed to make it past the group stage. At HOT6iX Champions Spring 2014, S failed to make it out of groups once again. The team's best result came at HOT6iX Champions Summer 2014 where they made it to the semifinals but ultimately placed 4th after losing 3-2 to the KT Rolster Arrows and then being swept 3-0 by Samsung White.

With the changes to the OGN rules, S and their sister team SK Telecom T1 K were forced to merge to form SK Telecom T1. With K's top laner, Impact, departing from the team, MaRin was given the starting position for top. The team participated in SBENU Champions Spring 2015 where they won the championship after beating the GE Tigers in the finals 3-0. SK Telecom's victory qualified them for the 2015 Mid-Season Invitational where they made it to finals but lost 3-2 to EDward Gaming. SKT placed first in the regular season of SBENU Champions Summer 2015 after only dropping one set the whole season. They beat KT Rolster 3-0 in the finals of the playoffs to qualify for the 2015 Season World Championship as the top seed from Korea. SKT was placed in a group at worlds alongside EDG, Bangkok Titans, and H2k Gaming. They went undefeated all the way to the finals, beating AHQ e-Sports Club and Origen in the playoffs along the way. They met the KOO Tigers in the finals and beat them 3-1 to give the organization its second World Championship. SKT played in the 2015 LoL KeSPA Cup where they lost 2-0 in the semifinals to Ever. This series is widely considered to be one of the greatest upsets in League history. MaRin left SK Telecom in November of 2015.