i think i misunderstood something, by 3 elements it means i can use light team+ another 2 random element kamihime, right?
and if the other 2 have to be in main team and not in sub, that means only 3 kamihime will get that bonus at time 'cause the other 2 have to be with different element.
i guess it can give some high bonus, but have lots of risks to it as well :S