The Elden Ring Fia questline is needed for the Age of Duskborn ending, a massive journey for the Deathbed Companion in which you'll slay an undead dragon and cross the world of Elden Ring to make things a little more necrotic. The climax is a battle with the Lichdragon Fortissax, a great challenge worthy of any tarnished warrior, but if you can crack it, you'll get one of the most unique (if gloomy) of all the Elden Ring endings set up for the finale.
To help you master this process, I've played it through and assembled a full walkthrough for Fia's questline, with all the key locations, tips for all the major challenges, and how to get all the key rewards involved too!
