So, I first need to premise with some WoB
So. We know that in Book 7, Wax had the Bands of Mourning, and he took the abilities of a Mistborn and a Full feruchemist out, as he demonstrates using different metals.
Now, later, when Wax threw the bands of mourning out of the airship. There was no mention of him returning the investiture, meaning he was still a fullborn during that encounter, albeit without metalminds for most of the metals.
later, when wax finally takes off the bands of mourning for good, it is never said that he returned the investiture, meaning he would’ve been a full-strength fullborn from that moment on.
also, this works just like memories with copperminds, if I take a memory out of a coppermind, I don’t lose access to that memory if I chuck the coppermind out a window.
This also happens to explain some crucial plot holes. For one, why are the bands drained? Wax never put the investiture back, so the bands don’t preform their key function, allowing one to store and retrieve unkeyed investiture. A water bottle is kinda useless if it’s empty.
it also explains why Wax got lerasium from the explosion. The justification for him burning pewter after the explosion is basically, “during the original experiment with trellium and harmonium, it created lerasium and wax then inhaled it and burned it.”
I find that incredibly stupid. For one, if wax inhaled lerasium, so would’ve everyone else, meaning Wayne, Marasi, and Steris would also already be mistborn. Second, why would he burn it? If a metal composition is off, it can make the allomancer very sick, and is potentially fatal. And yet, when a new reserve appears out of nowhere, Wax burns it. Am I the only person who finds that weird?
now, if Wax was a fullborn from the moment he used the bands of mourning, this would just be Harmony trying to make him not realize it. The best way to keep the bands of mourning from being used is to make the person who has the power, not know they have it.
As for why Wax never put the investiture back, I doubt he knew, information about nicrosil ferrings is very scarce, and wax was accustomed to iron feruchemy.
Edit: I just realized I never put my point in here. Basically, I think it’s possible that this is what happened, what are yalls thoughts/what implications does this have on future eras of mistborn?