Description[]
"Afflicts the <clan name> when we oppose them in raids"
This treasure hinders a specific clan whenever you fight against them during a raid.
It is not a unique item, and there is even a version called the Berenbane Banner, which will hinder your clan whenever it fights against those who possess it.
Acquisition[]
In Lights Going Out, the generic variant can be bought for 25 goods from a wandering trader that visits your clan, see the Trader Offers Bane Banner event.
The player specific version can be acquired in the event Berenbane Banner Appears.