Axel

Ranked as VIII in Organization XIII, he is a member gone rogue. He resides with the group in The Castle That Never Was.

Key Plot Points
Since Axel is preoccupied with reuniting with Roxas, he fails to notice that new nobodies have been inducted into the Organization.

Demise
Axel sacrificed himself to clear the passageway for Sora & Company to pass through to The World That Never Was. After his defeat, Organization XIII was reduced to just 4 of it's original members.