The Bronze Guarder is a giant armored knight found in a special room in the Clock Tower of Castle B. He's not very offensive, though, and just dedicates to walk forward at a steady, albeit very slow, pace. He can be dispatched easily with most means of attack.
The room where he's encountered in, however, has a few peculiarities. It features a pressure plate near the entrance that, when stepped upon, will activate an apparatus attached to the ceiling, sending out a gigantic hammer swinging forward.
If Juste stays near the entrance, waiting for the Bronze Guarder to approach close enough, and then steps on the plate, the hammer will hit him with great force and send him flying all across the room, making it crash on the far wall, destroying both it and the knight, and giving Juste access to a secret area with a minigame and valuable loot.