The (Sarina and Eloise Okestroise) sisters are the daughters of a merchant family of Baven in the Barony of Fandelok. They were educated by the wizard Rasher the Spirit Walker of Vale Evander. It was understood to be merely a transactional situation, his other 2 apprentices being “true” apprentices that would carry on his practice. The sisters learned the arts of recognizing non material presence and to tailor magic against such. When the spirits started going into Lilymarch, the baroness there sent her herald to Dunstrand City to hire the most powerful troubleshooters. House Malor recommended the sisters, having just come from the south seeking to find work against Gwinn – it was understood having been trained in the midst of the Steel League of the South (Vale Evander), that their sympathies could be best leveraged in Dunstrand. They traveled to Lilymarch, and to Ashfall, and although they were rumored to have sought Apshai in the swamp and not finding it, they were able to neutralize the threat temporarily. Their real motivation is seeking power from ruins referenced in ancient texts… What is now Scar Flow is hiding the Apshai temple that they seek to control. They will try and force others away from the area.
They employed a ghost beacon – really the spirits are just drawn to an area in Calibans Slurry. This is to get them out of the way and be able to track them back from the beacon to Apshai temple.