Under the Essence Drain power in 5ECRB, it states if a victim is drained to zero essence, the victim dies.
And, on page 23, is a bit of fluff:
"But it’s not free. And we’re not just talking money; there’s a higher price to pay. All this stuff is useful and great, but it’s artificial. It’s not metahuman, and your body knows it. Each time you get one of these augmentations, you give up a piece of yourself. You lose something inside of you, the essence of metahumanity. We don’t quite understand what this “it” is, but we know this much—the more artificial you make yourself, the farther you get from actual life. If you get too far, whatever animated you is going to disappear, until all the gear you bought just collapses and becomes indistinguishable from any other pile of silicon, steel, and chrome. So go ahead and get yourself augmented up. Get those synaptic boosters, those muscle replacements, and while you’re at it put a sparkling datajack in your head and some boss, day-glo nano-tattoos on your face. Just understand that each time you do this, another piece of your metahumanity goes sliding away."