The player can't save everyone in Elden Ring, but there are a few characters they can help -- although it might not be easy.

Sellen is located at Waypoint Ruins in Liurnia of the Lakes ... and reach the top of the tower to find both the Stargazer Heirloom and the Cursemark of Death.

The Moorth Ruins is a location in the Elden Ring DLC, Shadow of the Erdtree. Located in the Scadu Altus region, you will run into this crumbled settlement while searching for a mysterious warrior ...

The Primal Glintstone Blade is a Talisman Introduced in Elden Ring. An old glintstone ... in the Mountaintops of the Giants, in the Stargazers' Ruins. You'll need the Spirit Jellyfish Ashes ...