Astral Crossbow

Loot from Endless Watcher in Zaviak's Vision Quest in Chapter 10.

In-game description
"The silvery string of this elegant weapon gleams like the silver strings connecting Astral Travelers to their bodies. Legends speak of a deva who crafted this weapon out of bits of soul from astral travelers, willingly given to the deva to forge a weapon of good. The deva passed the crossbow down to a champion of good on the mortal Plane, who wielded it for many years before falling under a glabrezu's claws."