The Angels
The Angels are beasts that come from outer space and attack Earth to destroy them. Again, that is what NERV wants us to believe. They are actually sort of humans, not aliens. In End of Evangelion, Misato says "Humans are the 18th Angel." Ritsuko also says that the DNA of humans and Angels are extremily close in Episode 5. There are a total of 18 Angels, including humans as the 18th. All the Angels were named in the Dead SeaScrolls (see Dead Sea Scrolls below). The first one was Adam (see below) and the second was Lillith (also see below). The rest of the Angels became more and more dangerous and stranger looking as time went on. They all tried to get to Adam or Lilith, but all of them failed until the 17th Angel, Kaoru Nagisa, got to Lilith and decided that he was tricked into destroying the human race and let Shinji kill him (see Kaoru Nagisa below). There is a lot about Angels in the Second Impact, but I'll leave that until when I explain the Second Impact below.
First Impact
First Impact was supposedly the first time that humanily almost reached it's final goal, or the final level of human evolution, but there are other thoughts on the subject. I have heard that the First Impact was the meteror that hit the planet and killed all the dinosaurs, but I don't have any reason to believe this. Being a very religion-based series, and more specifically a Christianity-based series, the First Impact was described to me a Noah and the flooding of the world. I think this is a better theory because of the religious aspect and the fact that it had to do with evil humans that treatened God's way of life. But, I have heard in numberous places, including the Red Cross Book, that the First Impact is the first theory, yet I still hold true to my own. Characters refer to the "Ark" in a few instances during the series and movies and I think that the Geofront represents the ark, but that is just personal opinion.
Second Impact
Second Impact is much more concrete than First Impact, but still is confusing. Second Impact occured during the year 2000 A.D. and almost destroyed the human race. NERV said that a meteror hit the continent of Antartica and vaporized all of the ice. What really happened is that humans there found the 1st Angel, Adam. They were doing experiments with it and it went out of wack. To reduce the damage done by it, they turned it into a embryo state, unfortunately releasing a whole lot of energy, causeing a massive explosion. Under the Angels section is a picture of the Giant of Light, which was a name of Adam. It seems to look like Unit 01 to me, which may have something to do with why Unit 01 is so important.
Misato Katsuragi, one of the main character in the series, was the only survivor in the Second Impact. Her father was the leader of the investigation and they brought Misato, only 14 at the time, along with them when they fooled around with Adam. With his last ounce of strength, Misato's father put her into a safe place and saved her life. Unfortunately, Misato "witnessed Hell firsthand" and was unable to speak for a long time, yet she eventually was able to pull out of it and join NERV.
Third Impact
The Third Impact was what occured in the End of Evangelion movie. Since Unit 01 was made up of pieces of Lillith (see below), Unit 01 was the main piece to the Third Impact. If you want to know exactly what went on during the Third Impact, read the summary in the Episodes section. But more or less, the Third Impact ended the world. Shinji was inside Unit 01 during this entire process so he was spared. It may have been that Rei was responsible for saving him, for she spoke his name before melding with Lillith in the movie. All the humans in the world were turned into LCL.
The image above shows all the people turned to LCL. A Rei stood by all of the people as they were turned. The reason for this phase shift is because all the people lost their AT Feild (see below).
In the end, Shinji chose to live in the world and not give up (that's pretty much what Episode 25 and 26 are about). He also chose to stay with Asuka, because I guess he likes her (why, I don't know. hehe :) ). Shinji then finds himself lying next to Asuka in the end of the world, surrounded by LCL fluids and crucified Evangelions. This is the last scene of the movie.
Seele and NERV
Seele means "soul" in German, or so I'm told (I don't have a German dictionary). Seele is represented by the seven eyes of Lilith (see below). Seele is lead by a man named Keel (the spelling is different all over the place) who I suppose is blind because he wears a Jordi La Forge (Star Trek) visor. Seele is seen in Episode 3 as five men sitting at a table (Keel is at the end and has no specific color to him). There are more members, which we see in later Episodes where all we see are large grey blocks and in End of Evangelion where we see Keel again before Third Impact occurs.
NERV is a section of Seele that is headed by Gendou Ikari, Shinji's father. Gendou founded the company, but I suppose that Seele had a lot to do with it, because Keel and the Committee have a lot of influence over NERV. Seele and Gendou seem to have different agendas, because Seele attacks NERV in End of Evangelion. NERV is also above the law in Japan, referenced many times, including in Episode 7 I believe, when Ristuko and Misato go to see JetAlone. They are the sole defenders against the Angels and hold the technology to stop them; the AT Feild (see below).
Lillith
Now here is a large subject. Lillith is the supposed first wife of Adam in Genesis, and was not made out of any part of Adam, as Eve was. Lillith and Adam had some sort of fight and Lilith was exiled from Eden. I have heard many different versions of this story, yet it seems that Lillith gave birth to demons and spirits. Lillith is the thing crucified on the red cross in Central Dogma in the LCL sea and wears a mask with the symbol of Seele on it (see above for the picture). The characters believed that this was Adam, until Kaoru Nagisa realized that it was in fact Lillith in Episode 24.
I wish that I could get a better picture, but until I find another one, this one will have to do. You can barely see the mask that Lillith wears, which as I said, bears the mark of Seele. Why it is crucified, I have no clue. It is half destroyed or something, from the looks of it on the bottom, and is in the condition that it is in now until the Spear of Longinus is pulled out by Unit 00 and Rei in Episode 21 or 22, where it then begins to grow again. Finally, it completes itself in End of Evangelion, when Rei enters it (see Third Impact).
Spear of Longinus
The Spear of Longinus is what was inside the chest of Lillith until Rei pulled it out in Unit 00. See above, but it isn't a great picture. The spear is actually what was used to pierce Jesus to see if he was dead; Longinus is the supposed name of the man who did it. It is used to kill the 15th Angel, something that pisses off Seele a lot because it doesn't have anything to do with what they though would happen, judging by what they read in the Dead Sea Scrolls (see below). The spear itself was lodged into the moon after Rei threw it at the 15th Angel and finally came back in End of Evangelion when it was used to make the Tree of Life. It has some significance with the Third Impact, yet I do not know what. It was needed to start the Third Impact, as well as complete it.
When attacking Unit 02 in End of Evangelion, the Eva Team (the white Evangelions with wings) used large weapons that were extremily heavy and difficult to use. When Unit 02 was beginning to win, these things changed into Spears of Longinus' and pretty much killed Unit 02. The Spears are very very very powerful, yet they can't be used to start the Third Impact; they are only copies. Only the origional Spear of Longinus can be used. My question is, how did it get so bloody big? If it pierced Jesus, wouldn't it be the size of a normal spear? I suppose it is because it is holy and special that it can grow and shrink at will.
AT FeildThe AT Feild is a thing that was talked about from the beginning of the series. In the opening credits, the words Absolute Terror Feild flash across the screen. Why it's called the Absolute Terror Feild is beyond me, because it is something that all humans possess, not to mention the angels and the Evangelions. It is our will, if I remember correctly, and holds us all together. It is something that actually binds us together. The definition of it reminds me of what Obi-Wan Kenobi said in A New Home (Star Wars Episode 4), something to the affect of "It surrounds us, it penetrates us, it binds the universe together." That's not the quote, but it is close to it. If it were not present, we would all turn into primordial ooze, or LCL (see above). The Evangelions and Angels use the AT Feild as a sheild that few things can penetrate. Kaurou Nagisa talks about it a lot in Episode 24. It is seen in almost every episode, so you don't have to listen closely to find it.
Adam
Adam is not as big a member of the cast as I thought at first, or at least as to what I know at this point. He is the first Angel, and the first human being (Bible, Garden of Eden, etc.). He was first seen being transported by Kaji Ryogi in episode 7, I believe, and mentioned as to be the thing in the basement of NERV headquaters over a few episodes by Kaji and Misato. It turns out that the thing was actually Lillith (see above).
Adam is the creature that the expidition into the Arctic found in 2000 A.D. He was tested and experiments were done on him until he went out of control. They tried to control it but it destroyed half the human population (see Second Impact for the entire story).
Well, my brain hurts from thinking of all these things, but I think I touched on all the important things there are to know. If I forgot something, please write me at kyuukai@hotmail.com. Thanks!