Ahh, but you can't discount the
beginning of that fantasy/nightmare. Chloe's very real attraction and desire for Davis - even knowing that he's a murderer - is made extremely clear.
Her later claim that she is doing "all this for Clark" is a half-truth at best, and an outright lie at worst.
Chloe has had far too many opportunities to be truthful with Clark about Davis, but she's made her choice to protect Davis. Sure, she can try and convince herself that she's doing this to protect Clark, but really, wouldn't locking Davis away in the PZ have been the much more sensible option for protecting Clark? As opposed to allowing him to roam the country with only her mortal self to supposedly keep him in check?
Chloe's not stupid, she didn't WANT Davis locked away, and it had nothing to do with thinking Clark would never forgive himself. The fact that she even said that to him was just...wow.
Davis made a calculated decision to switch from murdering Jimmy to murdering Ollie. The key here is that he wasn't DOOMSDAY when he made that decision - he was still Davis Bloom (just really sweaty). To justify that with him simply trying to control the beast is basically saying
I'm going to commit murder now, so that I don't murder anyone later. Which is deep in wtf territory.
This really is shining a terrible and revealing light on Chloe. Characters often end up doing things that you might not like - Lois making up the Stiletto story, Lana holding Lionel prisoner, etc. - but just because you don't like it, doesn't mean it didn't happen.
The difference here, as I see it, is I'm not sure how they can ever bring Chloe back from this. Lois was shown to fully regret her actions and learn from them, Lana was shown to admit she was teetering on a dark edge and willfully pulled herself back. Chloe is endangering THE PLANET, not to mention harboring the one creature who can kill Clark. It's too far out there for a comeback, IMO, but I suspect they will try.
And of course, Clark will forgive her, because he's Clark and that's what he does.
I'm almost tempted to check out TWOP just to see if the lemmings are all lined up on the cliff's edge. But, naaah. I'm sure they are somehow going to twist all this into being Clark's fault, or maybe even Lana's. Old habits die hard.