A phylactery is a small, enchanted box made from syanthazoa that is used be Venerable to preserve their knots upon their demise. Every Venerable is, upon being conceived and having reached a point of maturity within the womb, is bound by a modified version of the Rite of Sennit to a phylactery stored in the Nascent Keep, so that, upon death, their knot will go into the phylactery and be able to be reused by the next generation.
Phylacteries are precious items in Thassal, and under constant heavy protection by the Tunba Azsiskari. There have been phylacteries constructed outside of Thassal by wizards and sorcerers who wish to preserve their own knot, for one reason or another, and their have been tales of naturally occurring phylacteries—trees of Amaranthine Deodar that have been found with the stored souls of some unknown generations or reefs of syanthazoa that have the knots of lost sailors within them. It is unknown how these things come to pass, but are an object of study among the Venerable for their potential application in the creation of new, better phylacteries.