Cortez Lavernan

Not much is known about the mysterious and malicious former nobleman from the Kingdom of Lucis, except that he was disgraced for his experiments, blames the Dragelion family and has sought out to destroy them no matter what world he ends up in. With his building army of daemons, he hopes to exercise his revenge, as well as gain control over Zephon so people may see things from his point of view, even if they all have to be daemons to see it that way. While he has killed and daemonified the rest of the Dragelion family, one remains - Caius Dragelion. And Cortez is in no hurry, seeming fully content to torment and torture his prey before he deals the killing blow. 

According to Cortez, Caius' father was the one to have him imprisoned, and turned his family against him. It was Cortez who killed his birth and adopted family, and it was he who attempted to assassinate Noctis Lucis Caelum before being brought to Zephon. While Cortez has disappeared for the time being, it is unlikely that this is the last we will see of him...