How to Find Nepheli Loux and Complete Her Quest

First Meeting - Stormveil Castle: From the Liftside Chamber Site of Grace, head along the path past the barricades and eagles to find Nepheli in a room. Alternatively, head south from the Secluded Cell Site of Grace, dealing with a Troll. Speak to her, then summon her for the Godrick the Grafted boss fight.

Second Meeting - Roundtable Hold: After defeating Godrick, return to Roundtable Hold. Nepheli will be outside Gideon Ofnir's room. Speak with her to receive the Arsenal Charm and exhaust her dialogue.

Third Meeting - Village of the Albinaurics: In southwest Liurnia, head from the Village of the Albinaurics Site of Grace under the large bridge. Speak to Nepheli and exhaust her dialogue. Then, head up the path and across the bridge to defeat the Omenkiller boss. Nepheli's gold summon sign will be to the left of a large rock near the firepit. Summon her to help defeat the Omenkiller.

Fourth Meeting - Roundtable Hold: After defeating the second Elden Lord, return to Roundtable Hold. Speak to Gideon Ofnir about Nepheli. Find Nepheli at the bottom of the stairs near Smithing Master Hewg. If you have a Potion from Preceptor Seluvis, you can give it to Gideon instead of Nepheli to progress her questline without ending it prematurely (though giving it to her results in her becoming a Spirit Ash). Speak to Nepheli after speaking with Gideon. You will need to travel to the Chapel of Anticipation (accessible via the Four Belfries in northwest Liurnia using the eastern Teleport with an Imbued Key). Defeat the Grafted Scion, then find The Stormhawk King key item in a hole in the wall at the back of the building. Return to Nepheli at Roundtable Hold and give her The Stormhawk King.

Final Meeting - Stormveil Castle: After reaching Crumbling Farum Azula, return to Roundtable Hold. Rest at the Site of Grace several times and exhaust dialogue between Smithing Master Hewg and Roderika. Ensure Kenneth Haight's quest is completed (he is looking for a new ruler). Rest at the Godrick the Grafted Site of Grace to refresh the area. Nepheli and Kenneth will be in the throne room, with Nepheli seemingly taking the role of ruler.