Sora killed them, it just doesn't show it because Nomura probably expects you to know who dealt the final blow. And when Donald or Goofy actually deal the killing hit to someone and actually KILL THEM, not injure them, KILL THEM, then I'll just put myself in an asylum. The Organization originally were wroking on studying memories (COM) and gathering hearts to build Kingdom Hearts (KHII). Theyre not really doing anything within that circle as their portrayal as evil or good; just doing what they know to their knowledge is what is the #1 thing at the time. They just get to mess with Sora alot, which to them seems as both an extra piece on the chessboard and a lab rat to experiment with memories on. Marluxia and Larxene were going to betray the Organization, and technically Vexen, for nearly telling Sora of Roxas' existence, which Axel puts out of any mind by slaying him before he imparts this to Sora. Xemnas, Xigbar, Xaldin, Luxhord, Saix, and Demyx pretty much attempt to do their little "assignments". Demyx gets pwned and dies the second time you face him. Saix gets to go after Axel, and messes with Sora, and dies by Sora's hand. Luxhord completes his "assignment", and gets cut down by Sora when he makes a kind of shield wall with hsi cards. Luxhord obviously doesn't know that a KeyBlade can cut through those flimsy cards. Poor guy. As for Xaldin, he keeps being a thorn in the Beast's footpaw by always trying to take the Beast's Enchanted Rose. For the last time Xaldin, don't make the Beast angry. He might turn green and start beating the living hellz out of you, along with Sora, Donald, and Goofy. Xigbar goes to get some tofu, and what happens? He runs into Sora. So he summons some of his Sniper Nobodies and runs off. Smart guy. And he dies, even though he was pretty hard to kill compared ot everyone else. Xemnas was a pushover. The guy was doing basically his Heartless tried to do. And he died, after like five freakin' battles, that little fag died. In other words, The Organization was trying to play "poke the brain" with Sora, Sora was being a bisch and killing them off for their shananagians, and Beast was always grumpy.
DA AND.