Use the torchkey on the beacon to open the door deeper into the Oldwalls. Head deeper into the area and use the purple torchkey upstairs. Use the floor switches to activate the bridges.
The lower level bridge leads to a beacon that can be activated with the purple torchkey. After fighting through the Bane, enter the opened door. In the locked container are Banetouched Gauntlets.
To access the recessed area by the room, you need to acquire the Emir Torchkey from Raetommon first, then circle back to the area. It contains the Sigil of Strength IV.