Spellbook Seller Elena:
Let me see...
According to the Ancient Scroll, you can use a Resonance Amulet to get the information from the Tablet of Vision. There are several tablets, and if you gather the information from all of them, you can get the forgotten power. The first tablet is south of the Tower of Insolence. Visit it while I finish translating.
Take this Resonance Amulet I found with the scroll. Come back later!