Ienzo

Ienzo was one of the six apprentices of Ansem the Wise who made his debut in Kingdom Hearts Birth by Sleep and Kingdom Hearts Birth by Sleep Final Mix. Ienzo is the original persona of Zexion; his existence continued on as Zexion after his fellow apprentice, Xehanort, led him to his gradual descent into darkness. Ienzo is also mentioned in the Secret Ansem Reports found in Kingdom Hearts II.

Kingdom Hearts Birth by Sleep
A young boy who speaks little--but his serene gaze suggests he sees much.

Even and the others at the castle are raising him since he has lost his parents.

Kingdom Hearts Birth by Sleep
Ienzo appears in Kingdom Hearts Birth by Sleep as a minor character with no speaking lines. His parents passed away for an unknown reason, given a home by Ansem in his castle and becoming the youngest of his apprentices. Disobeying the orders of his master to stay inside the castle, Ienzo was ultimately surrounded and attacked by Unversed until Ventus comes to his rescue.

Shortly after the battle, his escort Even arrives and gives Ventus both his and Ienzo's thanks, explains Ienzo's past and that he had been assigned to look after the boy, giving Ventus the directions to the Castle Garden where he would find Terra before taking Ienzo back to the castle.

Blank Points
As Braig is interrogating Xehanort on his state of mind, Ienzo and Ansem walk past, eating sea-salt ice cream. The pair stop and turn to see Braig and Xehanort walking away, still deep in conversation.

Between Kingdom Hearts Birth by Sleep and Kingdom Hearts 358/2 Days
In the year following the events of Birth by Sleep, Ienzo participates in Ansem's research on the darkness in hearts alongside Braig, Dilan, Even, Aeleus, and Xehanort. It would be Ienzo's persuasive influence that convinced Ansem to build a laboratory in the castle's basement to conduct the experiment on Xehanort. But though Ansem decided not to proceed further, Ienzo and the other apprentices had their own intentions and continue conducting inhumane experiments on the human heart that ultimately results in the mass production of the Heartless.

Ansem quickly discovered their secret experiments, and immediately ordered them to stop. One day, after being advised to review their research data by King Mickey, Ansem found that the effects of their experiments had become irreversible before his apprentices banished him to the Realm of Darkness. Eventually, Ienzo and the other five apprentices dabbled too deeply into darkness through their continued experiments. Ienzo, along with the others, was consumed by the darkness, producing a Heartless. However, the apprentices all had strong wills, and so Ienzo became a Nobody ultimately named Zexion, one of the founding members of Organization XIII.

Appearance
As a child during the events of Birth by Sleep, Ienzo wears a white coat, with the sleeves folded back, over a black, V-neck top with a white collar. He also wears blue pants and navy blue shoes, as opposed to the other older apprentices' black boots. He resembles his adult self, and Nobody incarntion, with a few minor changes such as shorter, lighter hair. His eyes also appear to be a lighter shade of blue.

In the upcoming Dream Drop Distance, having grown up, Ienzo's appearance matches his Nobody's exactly but wears a long white lab coat, grey vest, white collared shirt, and a purple ascot.

Kingdom Hearts 3D: Dream Drop Distance
After both his Heartless and Nobody had been defeated, Ienzo appeared during Kingdom Hearts 3D Jump Festa trailer, resembling Zexion with a slight difference. He is first seen talking with Aeleus before Lea finds them in Ansem's Study. In another scene, Ienzo and Even are both knocked out by Xehanort prior to the Heartless attack on Radiant Garden, which is possibly when he became a Nobody.

Notes and references
Ienzo