Pyohun was one of Uisang's ten major disciples. He became the first head monk of Pulguksa in Kyongju. He was an advisor to King Kyongdok or Shilla. In addition, he was chosen as one of ten "Saints of Shilla" and inshrined at Hungnyongsa after his death.
Here is a translation of Buddhapia.com's brief biography of Pyohun.