The Ancient Vows quest is one of the more confusing ones you'll get in Path of Exile 2, and that's saying a lot for a game which is generally very good at telling you where to go. You likely acquired this quest during the act two storyline while battling your way through the Mastodon Badlands. One of the enemies will have dropped the Sun Clan Relic and picking it up will have started the quest.
The problem? There's zero guidance—it just tells you to find a purpose for the relic. That's where I come in. Here I'll explain where to find the second relic you need and what you're actually supposed to do with them.
As mentioned, you'll get the Sun Clan Relic while fighting enemies in the Mastodon Badlands during the act two story as a random drop. But you'll also need the Kabala Clan Relic, which drops via defeating enemies in Keth; another area you'll visit during the story.
Once you have both relics, you're ready to complete the quest. You need to head to the Valley of the Titans, which you can find in the south of the desert map. Once there, explore until you find and unlock the area waypoint. If you've already been here as part of the story, simply fast travel to the waypoint instead.
Just next to it, you'll find a staircase leading up to an altar labelled 'Medallion' and as you get close an area banner saying 'Offering to Amrit' will appear. Click where it says Medallion and then drag each relic from your inventory into the slot that appears on-screen. This will complete the quest and make two buffs appear:
This is essentially a permanent buff and you can activate either by clicking on it, though you can always return later and click the other side of the medallion to swap to that buff instead. Either way, you can only have one of the two buffs active at once.
