After lending a helping hand to the four Sages in The Legend of Zelda: Tears of the Kingdom, Link sets out on an adventure to Find the Fifth Sage as per Purah's directions. In order to start the Find The Fifth Sage quest in Legend of Zelda: Tears of the Kingdom, players first need to complete the Crisis at Hyrule Castle - The Floating Castle quest along with the Regional Phenomena questline.
Considering that the Regional Phenomena questline is quite comprehensive, it might take players quite a while before they are able to unlock this quest. Once players have completed the aforementioned quests, they can head back to Purah at Lookout Landing to get the quest.
Completing The Quest
While the quest itself doesn't involve a lot to do, it branches into two separate quests for which you need some preparation, otherwise, things might get quite difficult for you. The quest requires 10 Heart Containers as well as the Camera, so if you don't have those, it is a good idea to get well-prepared for jumping into it. In order to get more Heart Containers, players must complete as many shrines as they can. Each shrine gives them a Light of Blessing, and four of them can be used to increase the number of Heart Containers you have. As far as the Camera is concerned, you should be able to get it by completing the Camera Works in the Depths quest, which is one of the first quests you encounter in the game.
Reaching Kakariko Village
As part of the Regional Phenomena questline, players would have visited and helped the four Sages, Sidon, Riju, Yunobo, and Tulin. However, there is another Sage, and players need to find them for this quest. Purah tells Link that players need to head to the Kakariko Village to proceed with the quest. Kakariko Village itself is located south of Lookout Landing and Lanaryu Wetlands. It might be possible that you have already been to the village while reaching Zora's domain. The closest Skyview Tower to the Kakariko Village is the Sahasra Slope Skyview Tower which is situated at 1344, -1170, 0166.
Kakariko Village is right east of this, and you need to head to coordinates 1816, -0951, and 0113 at Kakariko Village. You will meet Tauro and Chief Paya at this location, and you need to interact with them to get the Secret of the Ring Ruins quest. Players will need to head to the Dracozu Lake and Thunderhead Isles for this quest, and completing it will unlock another quest, Guidance from Ages Past, which will send them back to the Depths. Once they have completed these quests, they can head back to Purah at Lookout Landing to complete the Find the Fifth Sage questline in Legend of Zelda: Tears of the Kingdom.