First of all, let me clear up some confusion. For those of you searching for the reference, it's in the Final Empire, not well of ascension, in on of the log book entries.
Second of all, CURSE YOU OOKLA AND YOUR SILLY MOK POSTS!
Thirdly, I think it's very probably that Brandon created these metals just as he created Atium. I like the idea of the two wells, but I have a question. If those two wells are both metals, does that make them they 17th and 18th metals? They wouldn't fit into the circle thingy then. But if they are both well-like then they are probably each other's compliment, and thus I don't think either can be the compliment of the 15th metal that Elend ate. I guess maybe neither of them are allomantic at all, and are something completely different.
So. There are two "wells," and the Mist Spirit protects both of them. Only, we don't know this, because the Mist Spirit has only been seen protecting the pool Fedik tried sampling, and the well below Luthadel. What if, what was considered the well of ascension in Alendi's time isn't what the Lord Ruler moved. What if the two "wells," sort of take turns gathering power, one each millennium. And the Lord Ruler took the power from his well of ascension, and then moved the other one containing Ruin to Luthadel, calling it the well of ascension, so that he could get the other one as well? DO you guys see what I'm saying? The Mist Spirit only guards one well, the one Ruin is trapped in. Preservation may or may not be trapped in the other well, but this is my theory. The Mist Spirit only guards one well. And that is the metal lake in Alendi's time, not what they CALL the well of ascension. The Lord Ruler then moves this pond to Luthadel, after taking power from the other well, in hopes of taking them both.
There are holes of course, one is that Ruin was altering the prophecies both times, and was taking Alendi to the other well... unless it was Preservation altering things last time, who knows? There is still a lot to be sorted out. What do you think guys?
And Vega just posted while I was getting this ready. I'm assuming he made this room where he did so he could be right over the "well," and feel it's power better? That's jsut my guess anyways.