A chest atop the library, you can climb using the shelves, it respawns a while after opening and drops the top or the bottom of the set randomly
I got the top, but when I opened it again I got a tome of naive-something that resets stats.
Is it random chance with other items too?
I recently got a tome of lesser experience there too, i don't know the exact loot table but i am certain the bunhost cosmetic set is in it
