I just get back from an awesome week at camp, and I find and explosion has happened in my absence. Here are my thoughts:
1. The "bumps," person is supposed to be a near character who looks at the earth in a scientific way and knows absolutely everything about allomancy and hemalurgy and feruchemy. At first I thought this was Preservation, but after reading that chapter, and the whole "unfortunately, I am the hero of ages," bit, I think it is the Mist Spirit. In life, it was the true hero of ages, who locked Ruin (and perhaps Preservation) away to stop their feuding that was tearing the world apart, and appeared to all the "pretender" heroes of ages, like Alendi and Vin, to stop them from freeing Ruin once the prophecy was changed, who were unintentionally trying to undo it's work.
2. Elend has grown up, and I agree with what you guys have to say about him. He's not as powerful as Vin though, and can't soothe koloss.
3. My guess is if Elend has two armies coming, then one is koloss and one isn't, and Vin isn't there with him, because she has to control the koloss she is leading, and if she is too far from them they break out of her soothing? She isn't as powerful as the lord ruler yet after all, and there's nothing worse than a koloss army suddenly killing their allies. So she's coming with the army, which can't travel as fast, as a single man on horseback, and Elend is simply delaying the other koloss until she gets there.
Thoughts. boy it's good to be back!
