Helm: Tree Sentinel Helm

Armour: Tree Sentinel Armor

Gauntlet: Tree Sentinel Gauntlets

Leggings: Tree Sentinel Greaves

Where To Find: 

(Click the link above to view the equipment and watch the getting video.)

To acquire this set, venture inside the Auriza Hero's Grave.

Securing the set involves destroying three specific Chariots within the area.