Hint: Upper level, northeast of upper Bionis' Leg, by finding the elevated passage that leads to a cave.
"Head to the top of the large waterfall on the Bionis' Leg and collect the Ether Wisdom."
Hint: Believer's Paradise. The passage that leads to the cave is guarded by level 76 Last Rhogul. The clock can be changed until the area is raining during the day or changed to night time to clear the Rhogul, allowing to enter the cave that leads to Believer's Paradise.