I recently came back after a long break and started up the last three seasons. I keep looting "Insight" from killing nightmares in Altars of Sorrow. In trying to figure out what it's for, I see "Legacy: The Sisters", which says I have 0/25 Insight. I've probably looted like 5-6 now though. That quest also says to get it from Savathun's Spire or Altars of "Summoning". Do I need to advance another quest? Is this quest bugged? Is it for something else? Thanks.