The Clan of the Gate (門の一族 Mon no Ichizoku) was a clan of powerful rune users. They were wiped out several hundred years before the events of Suikoden but their two surviving members still influenced the Gate Rune War.
Hundreds of years ago the Clan of the Gate, were powerful people. But because of their power, they were massacred by the Holy Kingdom of Harmonia. Windy and Leknaat managed to escape, using the power of the Gate Rune. Windy would go on to look for vengeance against the entire world, searching for the Rune of Life and Death.