Used to upgrade Wrath of the Machine raid gear. 10 of these can also be consumed to create a SIVA Cache Key, which opens SIVA Caches in the Wrath of the Machine raid.
― In-game description
SIVA Key Fragments are materials used to reroll perks from Wrath of the Machine weapons and armor. Ten of them can be converted into a SIVA Cache Key.
SIVA Key Fragments can be earned by opening chests and killing ultras in Wrath of the Machine. A Guardian will earn three Fragments the first time an ultra is killed in a week, two the second time, one the third time, and none after that.[1] A SIVA Cache Key can also be broken down into ten SIVA Key Fragments.