ASHEN - White Ashen Feather 13 Location
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The 13th White Ashen Feather can be found in the Featherlands. Here's the direct path to it from the Bronzed Mire Ritual Stone.
This video is a part of the ASHEN - Weapon, Armor, Shield & Feather Locations playlist: https://www.youtube.com/playlist?list=PLsxfoGQwyeP42HmRSxCgVw5PASYMMbJxQ