Huh. It occurs to me that Death Battle may have been onto something by assuming “True God” status makes you immune to Ki/Life Force Stealing and could explain Buu. (The example they used).
Shin and Kibito are, interestingly, incompatible with the Energy Robbery methods Babidi used (Magic.) Now, technically, it’s not hard proof, nor does it actually establish actual, concrete resistance, but it is interesting and could explain why Buu (who absorbed a Kai) could not be affected by Moro’s Energy Robbery method (Magic).
It’s just a nugget for thought as I consider what I’ve been looking over, recently.