Sora kills off a large proportion of them in both Kingdom Hearts 2 and Chain of Memories. Here they are in roughly the right order:
Xion is defeated by Roxas, who is unaware of his actions
Vexen is incinerated by Axel
Larxene is defeated by Sora and fades into darkness
Marluxia is defeated by Sora and has an epic death sequence
Lexeaus is slashed through his stomach by Riku Replica, who is possessed by Ansem
Zexion is strangled and drained of his life energy by Riku Replica, who is being manipulated by Axel
Demyx is defeated by Sora
Xaldin is defeated by Sora
Xigbar is defeated by Sora
Luxord is defeated by Sora
Saix is defeated by Sora
Roxas merges with Sora, so does not technically die
Xemnas is defeated by both Sora and Riku
That's because in Kingdom Hearts 1 when Sora turns the keyblade on himself he turns into a heartless and that created Roxas as Sora's Nobody. Roxas became a part of the Organization of Nobodies Organization VIII and that's what brought the organization into Kingdom Hearts at all. But it was at the End of Kingdom Hearts so they put the organization in Kingdom Hearts Chain of Memories and Kingdom Hearts 2.
Riku kills him
Roxas kills her...the end is also very dramatic
I suppose your thinking about Kingdom Hearts. Since the entire Organization are Nobodies, they obviously don't have hearts. Their goal is to complete Kingdom Hearts (not as in the game series, as in the moon) so they can get their hearts back.
Kingdom Hearts is the collection of hearts that the Organization XIII has, they are the hearts that Sora took from the heartless, the hearts rose up from the dead heartless and went to Kingdom Hearts, which is in The World That Never Was.
no...its mickey mouse or in kingdom hearts king mickey the leader of the organization is Xemnas
in kingdom hearts 3, sora isn't in kingdom hearts partial he kills himself to be reborned to make sure kairi is alive. riku is in the side of the darkness, riku is half of sora and sora is the future leader in organization XIII
I'm not sure about that but there's a kingdom hearts ds game kingdom hearts 358/2 days. It's about Roxas in the organization XII
I'm not sure but i would guess that sense the keyblade is basicaly the only thing that can kill nobodies and when someone becomes a heartless a nobody is created and everytime the keyblade kills a heartless a hearts is sent up to the kingdom of hearts. and the members of organization 13 need kingdom hearts to become whole. so the keyblade is used to shut the door to darkness and to OPEN the door to LIGHT.
It actually is! It will be called Kingdom Hearts: 358/2 Days. It will feature Roxas in his time in the Organization.
Everybody from Organization XIII is made by the maker of Kingdom Hearts, they are not used from another Disney program
Xigbar/Braig