Of course, all creatures.
Well, let me back that up a bit. I would assume it would apply to immortal creatures as the spell doesn't 'target' them. But, Element's mechanics might not work that way. I would assume immortal text would read, "can't be affected by spells or abilities" instead of, "Can't be targeted" if immortal creatures were meant to be immune to non-targeted spells like this.
But, this could just be my lack of knowledge.
At any rate, my intention was that it would apply to immortal creatures as well as any other.
