From Granblue Fantasy Wiki
Zephyr Feather is a feather born of a calming wind. It is a silver quest treasure from Port Breeze Archipelago.
|Buy various items from the Treasure shop||5|
|Upgrade Revenant Weapons (step 3)||300|
|Obtain Ring of Raphael (SR)||3|
|Uncap Ring of Raphael (SR) to 2★||20|
|Uncap SSR Tiamat Omega Weapons to 4★||100|