Knights of Izumo

The Knights of Izumo is one of the Thirteen Chivalric Orders that guards the Japanese server in Elder Tale. After the Apocalypse however, they mysteriously disappeared.

Overview
Before the Apocalypse, the Knights of Izumo was a faction comprised of Ancients, immensely powerful People of the Land. Sometimes, when large-scale quests like the Return of the Goblin King weren't cleared out in time, the Knights of Izumo would step in to protect the People of the Land.

After the Apocalypse, however, the Knights of Izumo vanished without a trace, their bases completely empty. Although they were actually all killed by the Genius monsters, none of the Adventurers or People of the Land were aware of that. With the status of the Knights a mystery, the nobles of the League of Freedom Cities Eastal decide to keep it a secret from the Round Table Alliance representatives when the nobles need the Adventurers to help fight the monsters that spawned in huge numbers as a result of the aforementioned quest. However, unlike the Izumo Knights, the Adventurers were not necessarily obligated to fight for the nobility, thereby causing much friction between the two sides.