Full Compounders

[Enter a username]

On one of my forums (found here), it ended up asking why nicrosil Ferrings didn't all end up with Lord Ruler-style compounding (which I'm going to say is called being a Full Compounder.)

Basically, Feruchemists can use nicrosil to store and tap Investiture. So, why don't they all make two distinct metalminds and tap one of them in order to burn the other? Does it not work like that? Has nobody thought of that? Are they all hiding that they've already done it?!? (Okay, that last one is pretty unlikely...) But why haven't they all done it and let everyone else also do it via unsealed metalminds?

[NameIess]

The reason that this wouldn't work is that we have no idea if they can change the type of investiture that they tap. A regular F-nicrosil ferring can only store their ability to store and tap F-nicrosil, so unless they can convert that investiture to A-nicrosil, then they cannot compound.

[Enter a username]

Okay then... But double nicrosil twinborn (or, now that I think about it, any twinborn with Feruchemal nicrosil) shouldn't have this problem, right?

[Mist she/her]

I think they would only have compounded nicrosil Investiture, not any of the other metals. 

[Frustration]

So you can only compound when the metals line up. Additionally when someone is both a Feruchemist, and a Mistborn it's called a FullBorn.

[Karger he/him]

1 hour ago, Frustration said:

Additionally when someone is both a Feruchemist, and a Mistborn it's called a FullBorn.

Interestingly that is a fan term not one that is canonical yet although Brandon himself now uses it. 

[Halyo_Alex he/him]

Also, we know that Nicrosil feruchemy stores discreet things like Copper feruchemy, rather than a reservoir of a particular trait like, say, pewter. So you would just be storing your "ability to burn/tap Nicrosil" in the nicrosilmind and then be either unable to burn it or incapable of retrieving your power from the metal.