[He grins at that. Maybe Rei wasn't quite so talkative with this one? Or did she not know him yet? There's the timeline issue to consider.]
The answer is relevant to both of our discussions, actually; I was created by SEELE, who ran NERV, to circumvent Ikari if - or rather, when - he stepped out of line. My entire purpose was to speed up the plan so that he couldn't take it over. Has the First Child not told you what happens when an Angel reunites with its father? What SEELE ultimately desired?
[Leaving him to figure out that Kaworu himself is the Angel in question. He's obviously clever, which makes him fun to play with a little.]