First off, bravo SE. Bringing in a minor character for future content really makes the world feel connected.

MINOR SPOILERS NOW< BIG SPOILERS LATER

Ok for the minor spoilers.
edda is an NPC adventurer that you encounter in the game. By level 20, you see her multiple times. This video does a good job at summarizing it.

Spoilers on hard mode content in video. YOU have been warned.
https://www.youtube.com/watch?v=JAD95ewh128

Sooooooo yeah things happen. And in quest line to return to Tam-Tara, you find out she's gone off the deep end. She turns her now dead lover into a demon,and you the asshole of an adventurer have to kill him. after doing so she *actually* goes off the deep end. In a ball off flames. No, that is not a metaphor, she goes poof. see video below.
https://www.youtube.com/watch?v=HMQqN_8ta9Q