What is "gwisil"

The Gwisil clan (Kwi-sil; 鬼室, Japanese: Kishitsu) were descendants of the Kings of Baekje and were very influential towards the end of the kingdom.

In 660, Baekje was attacked by the allied armies of Silla and Tang Dynasty China. The capital, Sabi, was taken, but Boksin resisted near modern-day Yesan. After King Uija's surrender to Tang, Boksin and the monk Dochim kindled a restoration movement. They sent for the prince Buyeo Pung, who had been living as a hostage in Yamato period Japan, an important Baekje ally. With some Japanese aid, they gathered the remnants of the Baekje army and launched a series of attacks on the Silla-Tang forces.

In 663, Silla and Tang counterattacked, and besieged the restoration movement at a fortress known as Juryu Castle . At this point Boksin appears to have betrayed the restoration movement. He had Dochim killed and sought to slay Prince Pung as well. However, Pung killed him first, and fled to Goguryeo. The restoration movement was destroyed shortly thereafter at the Battle of Baekgang.