So I watched a YouTube playthrough. I'm glad I did, it's over in half an hour and really it is just a Caius fight (albeit a hard one-on-one). However, it does give that 13-3 set-up. But it's full of the emotional speeches that tend to run-on and are worth next to nothing unless you're really invested into the characters/plot. Serah and Lightning go on about "having hope" and all that. Meanwhile, you get to hear Yuel chipping in a bit by essentially saying the equivalent of: "I hate to say I told you so...but I TOLD YOU SO" about what happened to Serah.
Hm. The game doesn't give much indication to having Serah revive somehow, rather this seem to solidify her staying dead with Serah's spirit having "no regrets" and this serving as a new "reason to fight" or whatever conviction for Lightning. A bit of a pain speaking you go through so much for her in the first game to only have her, more or less, die again here.
The plot for this game is ridiculous as is... don't know what magic tricks they're gonna slug out for the 3rd go around.
Oddly enough, I hope it comes out quick to finish it. Nothing like a good cliffhanger even on a bad story to keep you coming back.