Heo "Huni" Seung-hoon started his League of Legends career as a part of the Samsung organization as a practice partner for the team, though he was never officially a substitute for the team.
The first team Huni officially joined was Fnatic in January 2015. Huni and the team's new roster had a successful Spring Split, finishing 2nd in the regular season with a 13-5 record, partly thanks to Huni's impressive performances on LissandraSquare.pngLissandra and RumbleSquare.pngRumble among other champions. This secured them a bye to the semifinals of the Spring Playoffs. Fnatic beat H2k-Gaming in their semifinal matchup, and went on to secure 1st place after taking a 3-2 win over Unicorns Of Love in the playoff final. This meant that Huni and the team would pick up 90 Championship Points towards qualification for the 2015 Season World Championship.
This also meant that Fnatic would represent Europe at the 2015 Mid-Season Invitational. Huni and the team had a relatively successful tournament, which they opened with a decisive win over Team SoloMid. The team also had a notably close group stage game with SK Telecom T1, but went on to lose the game. Fnatic finished the group stage in 4th place, meaning they would advance to the bracket stage. They faced SK Telecom T1 in the semifinals, this time playing out a close series, but ultimately losing 3-2.
Now with Rekkles on the roster instead of Steeelback, Huni and the team went into the Summer Season with confidence running high after their performance on the international stage. Fnatic finished the regular season with a perfect, unbeaten 18-0 record - and became the first team to achieve this in League Championship Series history. This meant a 1st place regular season finish for the team and a bye to the semifinals of the Summer Playoffs. Fnatic went on to win the playoffs, beating Origen 3-2 in a tight final. This qualified the team for the 2015 World Championship, where they would compete as Europe's #1 seed.
At the 2015 World Championship, Fnatic were seeded into Group B along with ahq e-Sports Club, Invictus Gaming, and Cloud9. They picked up 4 wins in the group, going unbeaten in the 2nd week of group stage games, meaning they would advance to the knockout stage of the tournament. In the quarterfinals, Fnatic beat EDward Gaming 3-0 before suffering a 3-0 loss to KOO Tigers in the semifinals, putting an end to their campaign.
Huni and Reignover left Fnatic in November to join Immortals in December 2015 together. With a lineup including the two ex-Fnatic players, Pobelter, WildTurtle, and Adrian, Immortals were expected to be one of the top teams in the LCS based on their roster, and for the first six weeks of the split they lived up to - and even surpassed - those expectations. Huni and Reignover together extended their regular-season LCS winstreak from 18 games in Europe to 32 games overall as the team didn't drop a single game prior to week 7. However, in week 7 that streak was snapped as the team lost one game to reigning champions Counter Logic Gaming in week 7. They won the rest of their regular season games, but as the season progressed further they looked weaker and weaker as a team, and even seemed to falter against the last-place Team Dignitas, needing to come back against them to pull out a win.
With a top seed clinched into the playoffs, Immortals were guaranteed to face the lowest-seed team that won in the quarterfinals. That team ended up being Team Solomid, who were on a strong upswing after a sixth-place regular season finish. Despite their seeding advantage, Immortals lost 3-0 to TSM, with both their play and also their drafts called into question. Huni's champion pool limitations were highlighted as he picked Lucian top in game 1, followed by Graves and Gangplank, ignoring the meta-favored tanks of Ekko and Maokai on patch 6.6. They came back the next week to beat Team Liquid and finish in third place overall, with Huni playing the much more conventional Gragas and Poppy.
Expectations for Immortals going into the Summer Season were again high, after they were one of only three NA teams not to change any players in the mid-season break, and while they nearly repeated their spring split record - this time dropping only two series in the new best of 3 format as opposed to 1 best of 1 - they were indisputably the second-best team in the league. TSM with new rookie star support Biofrost went 17-1 in series, and they bested Immortals in both of their head-to-head series. Immortals still had a playoff bye, and so they were able to avoid TSM in the semis, instead facing the third-place Cloud9. In a back-and-forth five-game series, Immortals were upset and faced CLG in the third-place match, which they came back from a disastrous game 1 to win 3-2. Unfortunately, despite their combined 33-3 regular season record, Immortals only had 120 Championship Points compared to CLG's 130, and so it was CLG who won the automatic second-place 2016 Season World Championship seed from North America. And even though Immortals had the top seed in the Regional Finals, they were upset once again by Cloud9, and their season ended short of Worlds. Huni left Immortals in December and joined SK Telecom T1.
SKT's Spring Season was very dominant as the team finished 1st with a 16-2 record. In the playoffs they defeated KT Rolster 3-0 in the finals to capture yet another LCK title and qualify for the 2017 Mid-Season Invitational. At MSI the team was once again very dominant, going 8-2 in the group stage. In the knockout phase they defeated Flash Wolves 3-0 in the semifinals and G2 Esports 3-1 in the finals to capture their second MSI title in a row. The Summer Season was the beginning of a huge slump for SKT. They finished 4th in the regular season and just did not look as dominant as they previously did. Huni was struggling to perform well and he taken out as the primary top laner for a lot of the split. In the playoffs SKT lost 1-3 to Longzhu Gaming in the finals, however Huni only got to play in two of the games. Despite this, SKT qualifed for the 2017 Season World Championship as South Korea's 2nd seed. Huni was chosen as SKT's main top laner for the event.
At Worlds they were placed in Group A along with Cloud9, EDward Gaming, and ahq e-Sports Club. Despite looking vulnerable in a lot of matches, SKT finished 1st in the group. In the Quarterfinals they were matched up against Misfits. Although they were expected to win easily, the series went to 5 game with SKT barely winning 3-2. In the Semifinals it was a similar story as they faced off against Royal Never Give Up and won 3-2 in yet another nail biting series. In the finals SKT was dethroned after an 0-3 loss to Samsung Galaxy, marking the first time SKT lost a Best of Five series at a World Championship. In November Huni left SKT and in the next month he joined Echo Fox and moved back to North America.