StarcloudSWG wrote...
I think it's the existence of the Prothean Cipher in Shepard's mind that makes him resistant to Reaper indoctrination. Not *immune*, just resistant. The presence of a separate mindset offers a kind of redundant self-correction that makes it harder for the indoctrination process to work. Combine that with Shepard's formidable willpower, and Shepard can be reached by Reaper indoctrination but it takes much, much longer to work.
As for the rest, yes, Shepard is a cyborg. There are artificial implants, organs, etc, most of which are highly experimental, blending inorganic elements within artificially created organic structures. What Shepard is NOT, is a brain in a metal shell.
Good and interesting way to put it.

In short, he is an anomaly, like Leviathan states. He's human, but alien. He's somewhat mechanical, yet really not. (And in my crazier thoughts, he's virtual, yet connected to the physical; don't worry, I'm ranting)
The result, anyway, is that he could be exposed to Indoctrination (take your IT hating and loving outta here), but he is NOT one to just fall for it. Instead, he is possibly the rare individual who might be able to weigh the pros and cons of all sides. Neither succumbing utterly to Reaper manipulations, nor fumbling into old Organic mistakes.