The real mother of
Asuka Langley Sohryu. She suffered
mental breakdown due to an accident during an experiment, and thereafter lived in a
dream world until committing
suicide. Her
soul appears to have been used in the core of
Eva-02.
Source: The End of Evangelion : Glossary contained within The End of Evangelion - Theatrical Program.
In
The End of Evangelion Asuka finally realises that her
mother had been with her all along and so proceeds to kick the crap out of the
JSSDF and the
Evangelion Mass-Production Models.