Kaworu is my most favorite character from Evangelion. And, he requires a bit of explanation...
There is a lot of controversy involved when one talks about Kaworu, the fifth child. Let me try to
explain a bit.
Nagisa Kaworu is a clone (like Rei) who is sent to NERV from SEELE. He was probably captured as an
embryo or created by them. There are, like in Rei's case, dummy plugs made of him. He knows that he is a clone,
but it is uncertain if the second Rei knew that she was a clone. We know that the third does. Kaworu presumably
contains the soul of Adam and Rei the soul of Lilith (hinted at in the Red Cross Book). He is also the seventeenth angel:
Tabris. He, like the other angels, is trying to return to Adam. He goes to Terminal Dogma but finds, instead of
Adam, Lilith. Since he is the Angel of Free Will, Kaworu can decide to continue his quest for Adam, or be killed by
Shinji. When he lets Shinji kill him he saves Shinji and the rest of mankind because and angel returning to Adam will
cause the destruction of mankind.
No, Kaworu and Shinji are not gay. Why? Well...Kaworu is an angel and the angels have no definite
sex, they have what I would call a "pure love" and sexuality doesn't really need to get thrown into it, and Shinji is attracted
to women!
"It is my destiny to live forever though my survival will bring
final destruction to the human race.
However, it is possible for me to be killed, and whether I
live or die makes no great difference.
In truth, death may be the only absolute freedom there is."
~Kaworu