[Nagot Gick Fel]

I've never seen a problem with Air Shield or Personal Luck, or any other 'personal' buff (target: self). Body ethereal, OTOH, is a ranged spell, and it affects all units in the targeted square. The few ethereal CSlaves you noticed were etherealized because the spell was cast onto the square they were in, not because the CMaster did cast Body Ethereal on himself.