Kay Seo, the main vocalist in Iron Monarch, is best known in the rock and metal scene for his incredible vocal range which spans between 3~4 octaves. Kay found his own inspiration from the legendary Korean singer Shin Hae Chul, from Band N.E.X.T

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Kay has been involved in many musical projects since 2002 as an actor, a musician, singer, and vocal instructor. He also spent many of his teen-years heavily dedicated to MMA (Mixed Martial Arts), specializing in Hapkido, Muay Thai, Kendo, and Judo. Kay also enjoys cooking, traveling and watching movies.