One of Zelda: Tears of the Kingdom's many side quests takes Link back to Zora's Domain to help out everybody's favorite shark-man Sidon. Completing 'Secret Treasure Under the Great Fish' will not only net Link some cool new armor, but also enhance Sidon's Sage Ability - something that could prove vital to gameplay. Read on to discover how to complete this side quest in Tears of the Kingdom, and receive the Vah Ruta Divine Helm in return.