While the Master Difficulty rating might give some people pause, this quest is fully henchable. Follow your map to next sprout. A spawn has three Corrupted Flowers and one Corrupted Root. If you kill the Corrupted Root first, the Flowers will die automatically. When you kill all of them, three to five Infectious Dementias will spawn. The quest is currently bugged, so you do not need to drop a sacred root to purify the area, rather, just kill the group and go onto the next one. Once all three groups are gone, go back to claim your reward.