Does Metal have to be Hemalurgically charged for Ruin to control someone?

Question

We have several examples of Hemalurgic spikes being used to control or manipulate a being:

• Kandra
• Inquisitors
• Koloss
• Vin
• Penrod
• Spook

However, Spook's letter in The Hero of Ages reads:

Vin,

My mind is clouded. A part of me wonders what is real anymore. Yet, one thing seems to press on me again and again. I must tell you something. I don't know if it will matter, but I must say it nonetheless.

The thing we fight is real. I have seen it. It tried to destroy me, and it tried to destroy the people of Urteau. It got control of me through a method I wasn't expecting. Metal. A little sliver of metal piercing my body. With that, it was able to twist my thoughts. It couldn't take complete control of me, like you control the koloss, but it did something similar, I think. Perhaps the piece of metal wasn't big enough. I don't know.

Either way, it appeared to me, taking the form of Kelsier. It did the same thing to the king here in Urteau. It is clever. It is subtle.

Be careful, Vin. Don't trust anyone pierced by metal! Even the smallest bit can taint a man.

Spook
_{The Hero of Ages - Chapter 69}

So I'm wondering if this is indeed true. I can only think of one example that would support any metal allowing control or manipulation.

The Lord Ruler said:

I fear that it has corrupted my thoughts. It cannot sense what I think, but it can speak inside of my head. Eight hundred years of this has made it difficult to trust my own mind. Sometimes, I hear the voices, and simply assume that I am mad.
_{The Hero of Ages - Chapter 48}

And in The Final Empire:

[Vin] flared the iron. Blue lines appeared pointing to the Lord Ruler’s rings and bracelets—all of them but the ones on his upper arms, piercing his skin.
_{The Final Empire - Chapter 38}

These bracers obviously were not Hemalurgically charged, because the Lord Ruler had no need for that being a full Mistborn and Feruchemist already. And yet it allowed Ruin to speak to his mind.

So is it truly any metal in a person allows control? If enough coins were shot into someone could they be controlled? What about Miles Hundredlives¹? Would Harmony be able to fully control him due to the number of piercings? Could the Lord Ruler have taken control of a Terris Steward² like he did the Koloss?

In short, does the Metal have to be Hemalurgically charged to control someone?

---

^{(all emphasis mine)}

_{1 - Miles Hundredlives}

“You need to get [Miles'] metalminds off of ’im,” Wayne said. “It’s the only way.”

“He keeps thirty different ones,” Waxillium said, “all piercing his skin,
_{The Alloy of Law - Chapter 13}

_{2 - Terris Steward}

“You’re a Terrisman,” Vin said. [Sazed's] earlobes had been stretched out, and the ears themselves contained studs that ran around their perimeter. He wore the lavish, colorful robes of a Terris steward
_{The Final Empire - Chapter 8}

Answer 1

Yes, the metal must be Hemalurgically charged

This effect is specific to Hemalurgy:

Hemalurgy is a very brutal way of making changes like this, though, so it often has monstrous effects. (Like with the koloss.) And in most cases, it leaves a kind of ‘hole’ in the spirit’s natural defenses, which is how Ruin was able to touch the souls of Hemalurgists directly.

It’s using a spike to “staple” this sort of power to oneself that creates the holes, because one is messing with one’s Spiritweb. Sticking a piece of ordinary metal in oneself does precisely nothing. I doubt sticking a piece of Feruchemically charged metal does anything, either, since it has no effect on the Spiritweb.

Spook doesn’t fully understand Hemalurgy. He doesn’t understand it at all, really. All he knows is that he was controlled through a piece of metal. So naturally he warns about all metal, which isn’t bad advice, since one can’t really know whether a given ornament is Hemalurgically charged.

It would be impossible for Ruin to control a Terris steward (at least in that manner). It would also be impossible for Harmony to control Miles Hundredlives (although, as the sole deity on Scadrial, he could do many other things to stop him if he desired).

It may be much as with Odium in the Stormlight Archive, another series set in the same universe, who could not control just any Parshendi. Bonding with a regular spren, as Parshendi do to change forms and Knights Radiant do when they take oaths, is not enough. It requires something more specific—a bond with a voidspren. This is probably another form of Spiritweb damage, that allows Odium access. (Although I can’t be sure that this works by making a hole in the Spiritweb; it could be simply that bonding with a spren whose power is “in resonance” with Odium is the cause).

As for the Lord Ruler, he did have Hemalurgic piercings.

Q: Did the Lord Ruler have any Hemalurgic spikes in him? It would seem he’d need to for Ruin to influence him, but it wasn’t mentioned. Or did his bracers work as spikes?

A: His arm bracers, which pierced his skin, were his spikes.

Certainly, he was a full Mistborn and Feruchemist, but that was not the limit of the power he could have attained. By taking Hemalurgic piercings, he could further increase his power in various areas.

In order for the Lord Ruler to effectively manipulate the populace, be worshipped as a god, crush all opposition, and suppress technology, he needed power far beyond what others had access to, and Hemalurgy was part of how he got it.