The Comprehensive Hemalurgy Thread

[Comatose]

I believe one of the eyespikes is iron (they are different metals), which works with you theory, but the steel spike is in the spine.
AS for your hemalurgy burning mists theory Reaves, my major hole is this: Repelling and Burning the mist would look different.
1.  When Vin burns the mists in book one, they are swirling about her, not being repelled.
2.  If, the mists were vanishing as you suggest and not being repelled, that swirling patterns would simply stop, but if they are being repelled, the patterns would swirl away from them, continueing the pattern.  The characters, framiliar with the mists, would be able to notice this, and thus if the mists WERE vanishing, Elend would have said "The mists are vanishing around you Vin," and not, "I think you're repelling them."

[Czanos]

He stepped forward. Though he could no longer see as normal men did--after all, he had large steel spikes driven point-first through his eyes--he could sense the room around him.

From the Mistborn 3 Prologue, but it's mentioned in several places that the eye spikes are indeed Steel.

[Comatose]

I was sure they were iron, and during Sazed's fight with marsh, doesn't he remark that the eye spikes are of different metals?

[Miyabi]

I was sure they were iron, and during Sazed's fight with marsh, doesn't he remark that the eye spikes are of different metals?

Yes, I believe he does.  I THINK that what's happening here is that one time they are perceived as Steel, but they are later seen closer and that reveals the truth behind them.

[Qarlin]

I just looked it up. There is a mention of them being Iron Eyes, but nothing about them being different metals. :/

[JCHancey]

But the real question is what part do they play? They are both Iron, we know that brass is in the heart, now what about the other 7?

[Qarlin]

But I believe they are actually made out of steel. Iron Eyes being a reference to Marsh's nickname.

[Reaves]

eh, whether they are iron or steel it matters not. both metals allow you to see allomantically

EDIT: actually, they are steel 
check Czanos' quote above

He stepped forward. Though he could no longer see as normal men did--after all, he had large steel spikes driven point-first through his eyes--he could sense the room around him.

[Comatose]

And we don't know that the brass one goes through the inquisitors heart, only that it goes through the sacrifices heart, in the Inquisitor it could be positioned anywhere!

[Qarlin]

Steel and Brass. We don't really know what other metals are used to make inquisitors, do we? Sazed mentions that different metals are used, but not which ones.

[Comatose]

a Brass spike and a feruchemist sacrifice, Brass stores warmth in feruchemy right, guess the old theory about a spike per power goes out the window doesn't it, well perhaps there is still a spike per power, just different ones than the sacrifice has, I can;t see inquisitors wasteing a full sacrifice on warmth!

[Qarlin]

I still think it could be one spike per power, or even a couple spikes for a power, but I agree that they're prolly not stealing powers from Feruchemists.

[Comatose]

Then the question is, why use feruchmists?  What's the benefit??

[Phaz]

Then the question is, why use feruchmists?  What's the benefit??

Based on the "hemalurgy is stealing power" theory I think feruchemists make lots of sense.   If using (Skaa) alomancers steals the alomancy power, then it makes sense that using feruchmests would mean that it steals their power and gives it to the inquisitor.  That would make some pretty bad ass inquisitors.

[JCHancey]

The spike would need to pierce the man's body, passing through the heart, then be driven into the body of the Inquisitor tied below

It doesn't say it has to be in the heart, but do they drive it through the heart because of the amount of blood that would be there? Could the spike actually be working as the vessel that carries the blood into the other person's body?