||Zero duplicates other beings gaining their appearance, voice, powers and memories.
||"Its cruel of you to make a scar on a woman's face"
Zero is a robot created my Dr. Clay. She was created to be the perfect spy for the doctor. The reason that Zero is such a perfect spy is that she captures a person who is close to the subject. She duplicates them then takes their place and learns the desired information. There is one fault in Zero's disguise. No matter what form she takes a mark appears somewhere on her body, usually somewhere concealable. This is because of Dr. Clay's ego. He likes to put his personal logo on his favorite things. After Zero's second to last mission, some of the traits her subject had remained. Zero's memory banks were wiped after the mission but somehow some traits remained. These traits manifested as emotions which Zero gained. This allowed her to break Clay's control over her. Ryoko's feelings that Zero copied were so strong that Zero fell in love with Tenchi. She couldn't bring herself to complete her mission because one of her objectives was to kill Tenchi.
After breaking Clay's control she came to like the feelings that she had for Tenchi and the affection that Tenchi showed for her. She wanted noting more than to become Ryoko. As a solution to this problem Washu combined Ryoko and Zero (with Ryoko's permission.) The result was a Ryoko that was more open to her feelings.
In episode 11 Zero was employed to replace Ryoko to capture
Washu. The transformation can be seen on the right... Looks like chocolate... Mmmmm Chocolate.... Who's hungry? Anyway, when Zero tried to copy Ryoko's gem on her wrist, her duplication was not successful. Nobody could figure out why the gem couldn't be copied so Zero removed the gem from Ryoko and placed it on her wrist.