Wall of Shadows
Defender (This creature can't attack.)
Prevent all damage that would be dealt to Wall of Shadows by creatures it's blocking.
Wall of Shadows can't be the target of spells that can target only Walls or of abilities that can target only Walls.
10/4/2004 Can be targeted by a modal spell that can target a non-Wall in one of its modes, even if it has a mode that targets only Walls. That spell can, in theory, target a non-Wall, so it is not a “spell that can target only Walls”.