Badge of Vows 28 is a quest item obtained during the quest From A Different Sky 3. The badge is the remnant of a former Rift Stone, collecting it earns a reward of rift crystals.
"A badge that glimmers with a mysterious light. Similar medals can be found scattered around Gransys."
The quest will only appear on the Notice Board if the location is accessible to the Arisen.
Enter the Soulflayer Canyon from the western entrance. When the path forks, take the path right across a wooden walkway to a wooden ladder. Descend to the bottom of the wooden scaffolding and slide down to Leaper's Ledge. The badge is located among the platforms of rocks.