From Battle of the Immortals Wiki
Lost Ruins takes place every Saturday between 14:00 and 18:00, server time. Participation rewards both a generous amount of EXP and the ability to acquire some of Quetzalcoatl's Treasure.
- - A party of three players is required (a full party of six is recommended).
- - Each character can only enter the Lost Ruins once per week.
- - After entering the Lost Ruins, the party has one hour to defeat 15 waves of Quetzalcoatl's Guardians, and then Quetzalcoatl himself. These Guardians are fairly strong, but non-aggressive, and they give excellent EXP.