User blog comment:The Maverick013/Angel Experimentation?/@comment-3244328-20120421015251/@comment-3103549-20120421044208

It seems odd to me, though, that there is this much development for the 3rd Angel, and not for others. I suppose we haven't seen such deep analysis of them, but even so, nothing really sticks out about their designs to make them as significant.

As for Lilith... she appears to be some kind of product of Seele's plan. Which brings me to the sequel theory, which seems highly probable... When I first considered this possibility, the first thing that came to mind was Lilith--notably, the spear and the mask. Why the change?

Personally, I think the sequel theory is quite possibly the most likely explanation, particularly for things such as the differences in Kaworu's behavior (and his lines...), as well as Lilith's differences. Sadly, the sequel theory as I see it is far too expansive to cover here... but it seems plausible, and highly connected to Lilith in this context.