Bahro pillar
From Guild of Archivists
Bahro pillars are round, bone-topped pillars approximately 5 feet tall. It is not clear how, but Yeesha claims that they are tied to the soul of an individual bahro. There are four pillars, which Yeesha indirectly tasks explorers with transporting from the "blue" bahro cave to Relto, and then back to the "orange" bahro cave in the Rudenna Passage in D'ni. By placing all four pillars in this "orange" cave, an explorer will release a bahro into the cavern, and a connection to the Star Fissure opens on the explorer's Relto.
When in Relto, the pillars have a blue-gray mist coming from the top, and glow less often than when in one of the caves.