Defeat Lucent Hive Guardians or Lucent Hive on Savathûn's throne world using Solar and Arc Light and claim the Witch Queen's runes from them. Slaying Hive anywhere in the system will occasionally yield traces of the Witch Queen's Runes.
To fool the Hive god of war, Xivu Arath, we were tasked with the collection of runes bearing Savathûn's mark, slaying Dark Hive, and planting those runes on the corpses of Xivu Arath's fallen forces. In doing this, we turn the sisters against each other.