Find Strangled Adra

Nestled within each of the primary four regions, as well as the final endgame area, is a single crystal called Strangled Adra. They’re a little larger than the Waystones you use to set up party camp and fast travel with. Interacting with the first four will give you the Adra introduced in that region. The last one doesn’t give anything but will count toward the Pillars of Eternity achievement.
While you could always keep trading equipment for every stronger piece you find, you’re bound to come across a weapon or piece of armor that you want to keep around for your Avowed journey. Make sure to be confident in your upgrades, since Adra isn’t widely available. Otherwise, have fun upgrading a cool-looking sword or an early game OP bow to Legendary if you want.