The Purifier

The Purifier, also sometimes called "The Box" or "The Cube" is an object which Kasdri Valmorn has claimed to have found in the woods near Highcrest, located directly above Kasdris Plaque. According to his story, he gave it to Sera, but was then tasked by Stelli'Aris to retrieve it, and bring it to her and Praeteris.
Kasdri claims to have absorbed some kind of strange power from the object, and was also apparently visited by Praeteris while trapped within a Spellscar, which is where he learned that the box was called a Purifier.
Upon Group Alpha's rescue of Beatrice Wyrmwater, Sera arrived and placed the First Vestige within the Purifier, its energy transferring into Beatrice and turning her formerly black scales to platinum.
According to Sera, crested on either side of the Purifier were two items that facilitated finding the Vestiges, which have been called the "Vestige Compasses". They are both currently missing, but Sirius Greymoon claims that one of them was in the possession of an old friend of his, and that there was a strong chance that they were hunting the Vestiges themselves.
Avaritio revealed that one of these compasses was in the possession of Renfri, The Wolf Queen, in the Dire Forest southeast of Westbrooke.
Donahue Hadeon asked Kasdri to retrieve the purifier for him, for as of yet unknown reasons.
Factus, after using the Legacy Rune, has discovered the Purifier is over a thousand years old.