Just finished Secret History after Era 1

I read Secret History after finishing Era 1 (thanks to the responses on my other post), and even though I don't know what it might spoil about Era 2, I don't think I'll regret it at all.

This gives me the exact closure I needed, knowing that Vin and Elend aren't just "quite happy where they are" as Sazed told Spook, but that they truly understand what love is and are at peace with their journey together, willingly going Beyond with smiles on their faces. I literally teared up seeing this🥲. I feel like this completes Vin's journey for me. Now I can finally grasp that "bittersweet" feeling everyone talks about. Before this, I just couldn't get past the sadness from the trilogy's ending, even though I knew all the events and outcomes were carefully woven and inevitable.

That said, WHAT'S WRONG WITH KELSIER? Everyone else, Vin, Ruin, even the Lord Ruler, goes Beyond in a state of fulfillment, yet Kelsier still decides to stay in this transient state? What happened to his love for Mare and Dockson? I loved Kelsier in Book 1 and appreciated his key role in defeating Ruin, but knowing that he's somehow active in Era 2 kind of annoys me.