thread/20687/SPOILERS-Five-Crosses-Six-spears/
There's been a lot of debate about the Fifth Cross at the South Pole, since it visually contradicts what we see in 2.0, both from the 2nd Impact flashback and from Gendo and Fuyutsuki looking at the Second Impact site from space, where there are distinctly 4 large crosses for the 4 Adams. Wether it's related to Eva 13 (and it's still confusing designation as an 'Adams survivor'), the Key of Nebuchadnezzar, both of these two, an unseen 'Fifth Adam' and whether it has always been there or was only 'shown' to us later.
One simple answer would be Lilith, who in 3.0 and Shin is visually associated with crosses that have fallen over. In 3.0 in Lilith's chamber, her cross is clearly depicted fallen over and to the left, at nearly the same angle as the Fifth Cross, and (I don't have a screenshot) is also shown fallen over in the images of Third Impact and Kaji's death with the Mark.06 on top of the beheaded Lilith.
It's likely this cross appeared after Third Impact (2nd Impact- 4 crosses appear, 3rd- 5th added) (less dramatically would be after what happens in Lilith's chamber in 3.0) as we don't see the South Pole between Gendo's space holiday in 2.0 and when the Wunder approaches it in Shin.
As for why a cross would appear for Lilith thousands of miles from the Black Moon there could be multiple answers. Fuyutsuki in Shin mentions 'the artificial recreation of Lilith' during Fourth Impact at Calvary. Other than ideas like how Calvary is clearly not an ordinary site, and the appearance of a large cross on an impacted Earth covered with large crosses thousands of miles away where the Moon's surface has also been transfigured doesn't stretch credulity.
I do have another theory (though it's only seconday so feel free to ignore it) that Lilith was present at 2nd Impact (either she was already present at Calvary, or was brought there as part of the Katsuragi expedition), that the white outline we see at the start of 1.0 is Lilith's (bit more of a stretch, but the outline from the angle we see it does also strikingly resemble Lilith's fallen cross) and she was blasted there after 2nd Impact -as most of the then most logical theories about the vessels of Adams have been superceeded by Shin, we could presume Lilith was the only thing flung away from 2nd Impact, and that rather than an Adam being ejected along with the bloodstain on the moon and being excavated and made into the Mark.06 by SEELE, which we now know would have to have bullseyed the circle of Kaworu coffins, SEELE chose to build their 'true' Evangelion here.