A brief run through of power orbs:

Okay: We know that all people in the senshi's universe have a heart cystal, a dream mirror, and a star seed(but only a senshi's shines forever, yadda yadda ya...) Well if a heart crystal represents a pure heart, a dream mirror represents beautiful dreams, and a star seed represents a pure soul(at least...I think it does...haven't seen Stars yet ^_^;) then our power orbs represent a senshi's power. So only senshi have them. You wouldn't die if these were taken out, only lose your powers until they were returned.