“Restoring the Zora Armor” is the name of the second quest that you must complete to advance the main Sidon of the Zora quest in The Legend of Zelda: Tears of the Kingdom.
The titular Zora Armor lets you swim up waterfalls in the game to access higher areas, at least once it is fully repaired. For that purpose, you need to find a mythical fish called the Ancient Arowana.
How to start the ‘Restoring the Zora Armor’ quest
Something important to note is that you do not automatically start the Zora Armor quest in Tears of the Kingdom. You have to find Yona who will not be marked on the map.
Make your way to Zora’s Domain in the eastern parts of Lanayru. Yona’s location has been marked on the map below. When you reach here, head to the Infirmary and you will find her.
She will be the green character in the pool. If you cannot find her in the Infirmary, you can look for her in Mipha’s court, where you met Sidon before.
When you talk to her, she will tell you about the repairing of the Zora Armor and that only one thing remains which is the Ancient Arowana.
You will have to find and bring the Ancient Arowana back to Yona. She suggests talking with Dento the blacksmith to get this fish but there are other ways to get the fish as well.
In Zelda: Tears of the Kingdom, Ancient Arowana is a common fish that you can use in cooking and can also be eaten Raw.
The Ancient Arowana is of significance to Yona because its fins can be used to repair the Zora Armor. The Zora Armor in Tears of the Kingdom is the same as that in BotW.
Where to find the Ancient Arowana in Tears of the Kingdom
You might have accidentally picked up the Ancient Arowana while questing in the Great Sky Island. If you did not, you can head back there to look for the ancient fish.
Start by fast-traveling to the Great Sky Island and then reach the southwestern part of the island. There is a waterfall you need to check. Its location is marked on the map below.
At the foot of the waterfall, you can find multiple Ancient Arowanas which you can catch by using electric arrows and electrocuting the water. They are also used in cooking so collecting a few can be helpful.
Ancient Arowana’s second location
The other location to find the Ancient Arowanas is to travel to the Fountain in the south of Mipha’s Court. From the Mipha’s Court, you can use the stairs can go up them until you reach the fountain.
If you have unlocked Ihen-a Shrine, you can fast-travel to it and then move towards the Fountain. The Ihen-a Shrine’s location is indicated in yellow.
If you haven’t unlocked the Ihen-a Shrine and are in Zora’s Domain. You can use the eastern path out of the Domain and move towards the Waterfall in Mikau Lake. There will be some stone steps which you can climb on.
Now using the Recall Spell, you can rewind time for the rocks and use them as a lift to move up the waterfall.
The Fountain, South of Mipha’s Court, is east of here but on a cliff, and with this lift you can get enough height to glide towards the fountain. After you have reached the fountain, jump off the ledge and glide back towards Zora’s Domain.
When you have acquired the Ancient Arowana and returned to Zora’s Domain, talk to Yona and give her the fish. She will then take it back to the blacksmith to restore the Zora armor in Tears of the Kingdom.
Upon returning, you will receive the Zora Armor chest piece. This armor will help you in moving up waterfalls and thus help in solving the problem of the sludge falling from the sky.
