Thanks for the translations DantesInferno!
For the FoIs with an Angel-like mask, looking at Jinroh's post with the images of the early version of 3.0, I think that this is the concept art of what the FoIs should had started to transform into when Fourth Impact happens, my guess is that this is supposed to be the final stage of the transformation of humanity into beings with FoI but without FoK.
DantesInferno wrote:Side note on the Mark.09... I never really understood how it gets its head blown off so easily by Eva-08's handgun shots, even though afterwards it is always depicted as being pretty much indestructible —even before "awakening": remember Mari's dialogue when she "snipes" it, and the ineffectiveness of the rounds at making any damage.
Perhaps the initial head we see was not the Mark.09's head morphed into the Eva-00 appearance, but just an attachment, a mechanical part made of regular materials (not core), and the actual head was in a "pulled in" state to make room. Durung the final act of the movie, the Mark.09 does not "regrow" a head, but it just pulls its actual head out (doesn't explain why they waited until 4I/unit awakening to do so though...).
That's an interesting theory, it's true that the recoil of Unit 08's pistol when it blows up Mark.09's head implies that it has a high caliber, but later in Lilith's Chamber, the same Mark.09 is hit several times by Unit 08's fuckhuge sniper rifle, which only manages to pin it on the floor without any damage.
Assuming that WILLE already fought the Adam's Vessels in the past, it's possible that the head we see them having in Thrice (the angel mask with their number engraved in Roman numeral on it) is their real face when they are in a "normal" state, and NERV just lobbed it off from Mark.09 and replaced it by a cyclops head attachment in order to trick Shinji into thinking that it was an upgraded EVA-00.
As for why they kept it headless for the incursion in Lilith's Chamber, well, why bother replace it? Mark.09 doesn't need to to function (or even for its pilot to see where she's going) and it'll regrow its head when Fourth Impact starts anyway.
What muddles the water with if WILLE already fought the Adam's Vessels is that the person who identifies it is Mari when she blows up its head, which normally would indicate that WILLE already knows about them, but with Thrice's revelation that she knew much more that she let on and kept a lot of knowledge to herself, with the implication that in a lot of her lines in 3.0 (notably when she identifies EVA-13 as one of the Adams, or that there shouldn't be a 13th Angel and understood Gendo's plan) she was actually talking to herself, I'm not so sure.