Quickly veer left if another boulder is following you (quite possible, regardless of where you left the pedestal's positioning in the upper room) and let any boulder roll past you. Then check the corpse hanging from a window along the right wall. You can check it to obtain the Covetous Gold Serpent Ring.

Along this path, you can also drop off to the side where you see a ledge with some scaffolding and an enemy to find the Large Soul of a Proud Soldier. Then you can explore the adjoining rooms to find another corpse where you can obtain the Black Sorcerer Hat, the Black Sorcerer Cloak, the Black Sorcerer Gauntlets, the Black Sorcerer Boots and Hush sorcery.