Definitions by Syretia
Xehanort
In the Kingdom Hearts series, he was the first apprentice of Ansem the Wise, having been discovered "on death's door" and afflicted with amnesia when he was young. He was Ansem's first test subject, and carried Ansem's experiments further than advised, even though he and the others were forbidden from any more experimentation and ordered to destroy the results of their past research. He eventually stole Ansem's identity and became a Heartless and a Nobody along with the others. His Nobody is Xemnas, the leader of Organization XIII. His Heartless was known as Ansem, but is simply Xehanort's Heartless.
zexy
"Sorry, Zexy. Saving you doesn't seem half as entertaining as observing Sora and Riku." -Axel, Kingdom Hearts: Chain of Memories
ienzo
The youngest apprentice of Ansem the Wise in the Kingdom Hearts series. He is the one who "enthusiastically advised" Ansem to create a new laboratory, and the Other of Zexion, meaning he is Zexion before he became a Nobody. Zexion's name is an anagram of Ienzo and the letter x.