The Light Stone, pure star marrow, and pure star source are the top soul elements for humans.

Among them, the pure star source is the most versatile and applicable. The pure star source potion made from it has a significant strengthening effect on everyone. Thalorian's current strength is largely due to the pure star source that Rode and others brought back from the Terror Fortress.

The Light Stone's use is more limited, currently only effective for those with the "light" soul trait. High-efficiency uses like the pure star source potion have not yet been developed.

Pure star marrow is similar; its only current use is for Rode to create Calles' Soul Cannon or to open a regular portal for the Spirit Boat. It hasn't been used on people yet.