OK - the above makes Gendou sound vaguely normal.
Gendou Ikari was a normal chapie up until somewhere around 2005, when his wife
Yui died (or alternatively was absorbed by
Unit 01) during an early
Evangelion activation test.
Shinji was sent away from home by his father - in many ways to protect him from Nerv and his father.
After this, Gendou turned in on himself, and became a hard-edged man that no-one could touch, someone who would use anyone and anything to achieve his goals. Even his son. Even his world.
Gendou is in charge of
Nerv - the top secret
UN organisation that is meant to be the last line of defense against the
Angel. The primary weapon for use against them was created by
Project E - the
Evangelions. These are fearsome creatures that are man's best attempt at building an
Angel.
However, this is just a cover up story -
Nerv and all of the technical might of
Eva is just a cover story for the
Human Instrumentality Project. The HIP is being run by Gendou Ikari for
Seele, the committee overseeing
Nerv. Gendou, however, is merely using
Seele and the
HIP to achieve his goals - returning his lost love
Yui to him.
The pawns in this game from Gendou's point of view are
Nerv,
Seele,
Shinji (his son),
Rei Ayanami, and
Dr Ritsuko Akagi. There are many more (
Kaji,
Misato Katsuraga,
Asuka Langley Soryu, etc...) but they are all sub points - minor items to manipulate, and if needed, to deal with.