MACKIAH
AMPERS&ONE · Rapper · Lyricist
Profile
MACKIAH (Mackiah Mercer, also known as Lee Ye-jun) is an Australian-raised rapper and songwriter of AMPERS&ONE. His international background and rap-oriented style are central to the group’s performance dynamic.
He joined FNC after a global audition in Australia and debuted with AMPERS&ONE in late 2023. His studio contribution increased as the group’s music moved towards heavier rhythmic concepts.
On the April 2026 DEFINITION EP, MACKIAH and KAMDEN jointly contributed lyrics to all six songs. MACKIAH said in an interview that exploring different styles in his rap writing had helped him become a more flexible musician.
His contributions are songwriting credits to a group album, not evidence of a separately released solo studio album.
Career Milestones & Individual Activities
Born To Define · European stages
Took part in AMPERS&ONE’s concert activities across six European cities.
K World Dream Awards
Received the group-level Global Next Leader recognition with fellow members; this is not an individual trophy.
DEFINITION and GOD
MACKIAH contributed to the fourth mini album and performed its title song. Individual lyric credits appear across all six album tracks.
DEFINITION · six-track lyric credits
Worked with KAMDEN on lyrics across the fourth mini album.
LOUD & PROUD
Contributed rap and group stage performance to the third EP.
FNC trainee selection
Joined FNC through the Australian selection event.
AMPERS&ONE debut
Joined the original seven-member lineup for On And On.
Member News & Further Reading
Agency notice lists six European stops and dates.
August 27, 2026 · FNC Official2026 K World Dream Awards group honour ↗Agency page lists the seven-member team’s Global Next Leader award.
June 18, 2026 · Korea JoongAng DailyAMPERS&ONE’s first European tour ↗Independent reporting on the September six-city concert programme.
April 28, 2026 · DAVIDE K-POPMACKIAH · Writing across every track on DEFINITION ↗A personal quote in an interview about DEFINITION and the group’s development.
April 14, 2026 · EARMILKMACKIAH in a DEFINITION group conversation ↗International member interview on composition, recording and ambition.
April 8, 2026 · Korea JoongAng DailyIndividual images from the Seoul showcase ↗Photographs and reporting on members during the DEFINITION press stage.
April 8, 2026 · Unclear MagazineMACKIAH’s answers on new music ↗Member interview covering identity, tracks and the group’s international fans.
2026 · FNC EntertainmentOfficial member profile, awards and albums ↗Primary label source for official group membership and dated releases.