"Pitiful Heartless, mindlessly collecting hearts. The rage of the keyblade releases those hearts. They gather in Darkness, masterless and free. Until they weave together to make, Kingdom Hearts. And when that time comes, we can truly, finally exist."
Saïx, narrating Organization XIII's plan
Saïx (voiced by Kirk Thornton) is the Nobody of Isa and a member of Organization XIII, ranked Number 7 and second in command to Xemnas. Originally, Saïx was a boy named Isa and best friends with Lea. After Isa and Lea were turned into Nobodies, they joined Organization XIII, changing their names to Saïx and Axel respectively. Just like the other members of the Organization, his goal was to reclaim the part of him that was missing: his heart. So he and the others tried to create Kingdom Hearts. Over the course of their time in Organization XIII, Saïx and Axel grew apart as Axel became friends with Roxas and Xion while Saïx became more ruthless and cold. Like his superior, Saïx is most like a Nobody, for he expresses no emotions and is very cold and calm. However, under the light of the moon, he enters into a mad berserker-like state. He met his demise after being defeated by Sora.
- Saïx will guest star in Jaden's Adventures of the NeverEnding Story.
- Saïx will appear in Jeffrey, Jaden & Friends' Storm Adventures of Kingdom Hearts: Dream Drop Distance.
- Saïx will become Hiccup's enemy in the future.
- Saix will become Twilight's enemy in Twilight's Adventures of Kingdom Hearts 2.
- Saix is part-Xehanort and therefore a member of the True Organization XIII.