Saïx/Isa

Saïx (voiced by Kirk Thornton), is the Nobody of Isa, Rank VII within Organization XIII, as well as the second-in-command to Xemnas and a major antagonist in Kingdom Hearts II, Kingdom Hearts II Final Mix and Kingdom Hearts 358/2 Days. He derives power from the Moon, and uses this power to enter a berserk rage where he mercilessly attacks opponents with his massive claymore. He commands the Berserker Nobodies.

Saïx is the second-to-last member of the Organization to fall. Along with all other Organization members in Kingdom Hearts 358/2 Days, Saïx is a playable character in Mission Mode.

Isa was the original persona of Saïx. He was a close friend of Lea, Axel's original form when the two lived in Radiant Garden.

In Kingdom Hearts Birth By Sleep, Isa meets Ventus in Radiant Garden and properly introduces himself with Lea. The two befriend him, though Isa is not as forthcoming as Lea is. Afterwards, at an unknown point in time, Isa's heart was consumed by darkness, turning him into a Heartless. However, his strong will gave him the ability to continue on as his Nobody, Saïx. Some time later, Saïx joins Organization XIII alongside Axel.