Jerga

Jerga (ジェルガ, Jeruga) is the general of the Gairadite Demon King Suppression Army and the King of Gairadite 2,000 years ago.

History
Jerga has a strong grudge against demons. After the wall was made and the Demon King died, it hadn't changed. The wall will disappear after 2000 years and the Demon King will reincarnate. He believed that the battle will not end until he completely destroys the Demon King. So he set up the Hero Academy to pass his resentment to his descendants.

But he was afraid that people would soon forget their hatred of demons. So he turned his root into two forms of magic. One is the magic Sanctuary  and the other one is the magic Root Womb .

He was later killed by Anos with Venuzdonoa after fighting with Anos and Kanon.