NOTE: I suppose it should have been mentioned, but if you are planning on reading any of Sanderson's books and want to avoid spoilers, you probably shouldn't be reading these posts. You have been warned.
Alright, where did I leave off?
Probably the most intriguing of the Mistborn magic systems. Feruchemy involves draining yourself of a certain attribute now (like strength, age, eyesight, or memories) in order to store that much of it in metal jewelry (essentially). Then, when you want to access it again, you can do so and gain a much needed boost to your naturally-endowed abilities.
What I like: Much better cost system than allomancy. I know I talked about how I liked allomancy's clear power source, but there's little actual cost in it. With feruchemy, you're actually investing a part of yourself in the magic. That makes it feel really tangible, and it creates even more precisely-defined limits on the power source.
What's not so great: Lineage. This goes for allomancy as well, in fact. I'm not a big fan of magic systems that are limited by bloodline. Now, they have their place and can be used well (as is the case here), but more often than not, authors limit their magic by lineage for convenience. Do you want only the chosen hero of the land to have magic? Okay, make it limited to his bloodline. Do you want just the king to have magic? Okay, limit it to his bloodline (although then you have some pesky heirs and cousins and distant bastard uncles to deal with, if you're being true to your world). Do you want these five characters to have access to magical powers without any reason or explanation for why or where the magic comes from and do you not want to worry about answer the question "why don't other characters learn the magic to challenge them?" Okay, say it's limited to bloodline.
Again, there are a lot of ways to do this well. But it seems to me that lineage is used more often as a part of lazy world building and storytelling, rather than as a dynamic source of conflict (or plot element) or as a compelling piece of lore enriching the world. So yeah, much as with the whole rant about the Force in Elantris. Feruchemy (and allomancy) loses points for ascribing to the lineage trope (even though it's used well here).
This is the one we know the least about. It's the most "evil" of the three Mistborn magic systems, as it involves shoving metal spikes through sensitive parts of a person's body (often after killing another person, I think). It's a bit unclear, as I recall, what effects hemalurgy creates, but I know it's often related to enhancing allomantic powers. The main purpose of hemalurgy, however, is its use in creating the monstrous servants of the Lord Ruler (the Koloss and the Steel Inquisitors.)
What I like: Mystery. There's really not a whole lot that I can say about hemalurgy, seeing as it's role is mostly in the background of the books, but one advantage that this background role gives this system is it's sense of unease and aura of mystery. You don't even know it exists for the first half of the series, and even once you do learn a few hints of how it works (thus making sense of about half a dozen scenes from earlier in the series) you are still left wondering as to the specifics. A few details seep out (arriving as they are discovered by our heroes, who are not the type to dabble in this form of magic), but we don't really learn any more than we need to in order to understand the smallest and most specific details of what is going on, rather than the big picture.
And I like this. It doesn't work as well when you try to do this with your main magic system (though there are exceptions, as with anything), but for a tertiary system like this, especially one used primarily by the series' villains, it adds a wonderful sense of the world being bigger than what we see in these few years of it's life. (By the way, this is one of the things that Sanderson does best. He tells a really compelling story from the world's history, but it's very clear by the end of it that you still don't know everything there is to know. Sometimes you aren't even sure if you know the most important things about the world. You just know the things you need to know in order to care about the conflict of the characters you're learning to love. It's both refreshing and infuriating.)
What's not so great: It's really hard to say, quite frankly, as we don't know a whole lot about the system. For that reason, I'm probably just going to leave this one empty for now. If more information about hemalurgy is revealed in later Mistborn books, I may revisit this topic in a later post.
Wrapping things up tomorrow.