The Dominator was a villain who appeared in "Episode XCVI".
Background
He was a villain who kidnapped an entire community of alien children and imprisoned them inside a factory. He also surgically implanted special chips in their neck which would result in children becoming extremely violent after the right audio frequency was used, changing how their brains would normally function and turning them into blood-thirsty creatures.
He forced the kids into attacking Jack and Ashi by activating the chips shortly after finding out that they had entered the factory. Jack sent Ashi to find the source and tried to outrun the alien children by himself.
The Dominator captured Ashi before she could accomplish her mission and started torturing her by shocking her while telling her about what he did to the aliens and how children could be easily manipulated. This reminded Ashi of how her sisters and herself were used as tools by their mother, which made her mad and gave her enough motivation to overcome 10,000 volts of electroshock, break free and kill him by throwing him into the control panel, causing it to explode.
It is unknown how the past Aku's destruction affects his existence. Since he lived and worked in Aku City, and the city presumably erased from existence, it is likely the same happened to him as well.
Appearance
The Dominator wore a red metallic suit with a metallic helmet for most of his screen time. This suit probably made him look much more bulky than he really was. His face was seen for a short amount of time after Ashi removed his helmet before killing him. He was a grown man with a red nose, gapped teeth, pink skin, brown hair and a brown mustache.
The Dominator's face before he is killed by Ashi.
Personality
The Dominator appeared to have a sadistic personality, since he kidnapped and enslaved a group of alien children without showing them any remorse and tried to make them kill Jack and Ashi. Furthermore, he clearly enjoyed torturing Ashi and made fun of Jack for refusing to take the life of the innocents.
He had no respect for personal space, as he touched Ashi's face several times against her will.