As with all other abilities, there are two choices for Wall's level IV upgrade.
One-Way Wall: Allows you to shoot projectiles through the wallOne-Way Wall is the perfect for defending and attacking at the same time. Since it allows anyone on the same side of the earthbender to shoot abilities at their foes, but anyone standing on the opposite side has all their projectiles blocked. </p>Earth Barricade: Wall stays up for longer, but uses up chi</p>This upgrade allows the wall to stay risen for a pretty long period of time. It's really useful for blocking off paths and stopping pursuers and enemies.</p></p>