KH pairings kind of obliterated by Days so far, IMHO: Axel/Demyx, Saix/Axel. Neither Demyx nor Saix show the slightest bit of concern when Axel seems to be dead.
(Demyx's exact words are something like, "Hey, did you hear the news? Everyone at Castle Oblivion got KO'd! Heavy stuff!" whereas Saix just casually suggests early on that Axel might have been the first Oblivionite to die. Xigbar joins the party by cheerfully suggesting that he could get used to having a smaller, more tight-knit group. Really, no one but Roxas seems to give a damn, it's kind of hilarious. XD)
In other news, Larxene's snark was awesome and perfect (from the very beginning, her response to Roxas is, "Eww, you're awake?", although when he becomes "semi-competent" she does seem to share Marluxia's opinion that it's too bad Roxas showed up when their plans were already underway because he might have made a nice addition to their conspiracy), and it seems that Xemnas actually did suspect the potential Oblivionite treachery, which I didn't expect.
Also awesome: Axel's simple description in the game manual which is something like: "Although he's a member of Organization XIII, when given the choice Axel prefers to side with Organization Himself." You can already see Roxas growing on him from their very first scene together, but that line is awesome.
...And so is like, every thing Demyx says. I have a feeling he'd be less snarky around Xemnas, but whoa, does he ever cut loose the moment the Oblivionites leave. Hello, Demyx Spine, it's nice to meet you.
Demyx calls Xigbar XIGGY. Zomg.