Mithril Horde I - Michele Laconto's Guide to the Storage Room, Lord Yuz's Palace
Find the four storage chests for Lady Sithra in Lord Yuz's palace.
As you eliminate the Ghosts in the Storage Room, they will drop:
Blue Storage Room Key
Gray Storage Room Key
Green Storage Room Key
Little Storage Room Key
The Red Storage Room Key will be found on a boarded up window in the hall to the south.
You'll find a chest in the room that the Blue Storage Key opens on a boarded up window.
The room with the number signs on the wall need to be tapped in this order: 7-3-9-5
The room in the center area that you become trapped in, you'll need to flip the three switches in this order: North-South-East then press the button on the west wall to open the door.
There's a chest in the pile of skulls in the northwest corner of the room with the switchplates on the floor.
Use the three chests that you have found, (Or two and stand in the last plate) to cause the wall at the end of the southern hall to open. Tap the gold circle decoration on the wall to find a chest.