Does the Magical Guard power, that spirits of the elements get, protect against spirit powers (such as Confusion)?

All I can find is that it works like spell defense. (Maybe I'll check and see if spell defense happens to offset spirit powers.) I didn't see an explanation of the power in MitS, where spirits of the elements are introduced.

It works exactly like spell defense and the only critter power spell defense protects against is "natural spell" (because it's really just limited spellcasting).

Thanks, that is what I was thinking after a quick look at the rules. I wondered if there was another explanation/definition I was missing.