Washu, The self proclaimed greatest scientist in the Universe. Her First appearance is in episode 6 of Tenchi Muyo. Trapped inside a Crystal on the "Mirrorside" of Kagato's Spaceship. where she was released for the first time in 5000 years.
Despite her age of 20,000 years Washu displays her self mostly as a girl in her early teens. but can adapt her physical age at any time to an adult form.
The reason for this is because her child and husband where taken from her. Since her husband came from a prestigious family, Washu was not approved the social status of the Family. Thus, she was not allowed to be with her family. Her hatred for these "adult rules" is why she'd rather be a child by appearance.
Her Child was Mikumo Kuramitsu, The great-grandfather of Mihoshi, making Mihoshi Washu's great-granddaughter.
Washu is responsible for creating the Soja, Ryo-ohki and Ryoko. Using her own egg cell as a base for Ryoko's creation, making Washu her mother.
Like Ryoko, Washu can create energy swords and blasts at will. She also has a telekinetic link with Ryo-ohki and Ryoko. Being able to read their memorys to some extent, this ability is not perfect as shown in episode 10 when she needed to connect Ryo-ohki to a machine in order to read her toughs. She can also create interdimentional portals near herself to dispose and create objects (Shown in episode 8).
Her main Goal is discovering the source of Tenchi's Power. She will go to almost any extent to get him as a guinea pig for her experiments, and strips him down to his undies for when it's not needed.
Washu (Washu-Kami-Sama) is one of the Choshin Goddesses along with Tsunami and Tokimi. but she gave up her immortality and powers to be able to unlock the secrets of the universe. Washu-Kami-Sama had 3 gems which contained her power and memories. These are the gems Ryoko uses for her powers.