The Absolute Terror Field
The central technology around which the power of the EVAs are derived, the AT Field is an important aspect of the battle sequences, as well as the overall plot. AT Fields can be generated by anything possessing a soul and a sentient consciousness. They are directly influenced by the power of their source and can be manipulated in a number of ways. They also hold the secret of the Third Impact and the Instrumentality.
Types of AT Fields
There are four types of AT Fields. The first is the basic latent field inherent in all living beings. The next two are derived from the first and take either a passive or aggressive stance. The final type is a collection of specialized versions - only one of which will be discussed here.
Latent
All sentient life forms possess an AT Field - according to Kaoru. This includes Angels, EVAs, and even Humans. This latent AT Field can go unnoticed for an individual's whole life. The AT Field is what holds the bodies of humans together and ties their consciousness to that same body. By this, the components of any physical being in the EVA universe can be described by the formula:
AT Field + LCL quantity = Physical Entity (with soul)
The latent field is the basis for all other AT Field types. When manifested, the AT Field can serve as a defensive barrier, an offensive weapon, or a tool to effect other AT Fields in the area. AT Fields do not become visible unless they are actively engaged in something - such as collision with matter, energy, or other AT Field.
Defensive
The most often used form, the defensive AT Field is seen several times during the course of the series. When activated, the defensive field will distort the space around it, creating a barrier. The field doesn't become visible until it is hit with by an attack, at which point the standard octagonal fluctuations in the field can be seen.
Offensive
Not seen too many times in the series, the offensive AT Field is the extension of a latent field in an aggressive manner. The offensive field can take on a couple of forms - either as a projection of the latent AT Field, or as a warping of the defensive AT Field. One of the more memorable offensive AT Fields is the one produced by Unit 01 during the battle with the Fourteenth Angel. After reactivating and regenerating its left arm, Unit 01 creates an offensive field that deflects the Angel's ribbon attack, shatters the Angel's AT Field, and causes massive damage to the Angel's body. Another instance of the offensive AT Field is seen during Asuka's battle against the JSSDF (see above pic). Although not a projection like Unit 01's, Unit 02's offensive field still does the necessary damage - taking out several tilt-engine air craft in one blow. Unit 02 offensive field seems to be produced by a warping of the defensive field so that it makes contact with nearby targets only.
Anti-AT Field
Seen only during the Third Impact, the Anti-AT Field plays an important role in the Instrumentality. These specialized fields can only be created with the aid of an S2 unit. The mass produced models' S2 engines go critical and their intertwined AT Fields merge with Lillith's into a singular Anti-AT Field. The purpose of this field is to counteract the AT Fields of the human race and reduce their bodies to LCL - from which their individual souls can be extracted.
It should also be noted that the Anti-AT Field's effects are seen earlier in the series - although it is not identified by name. After Unit 01's acquisition of an S2 organ, Shinji's body is turned into LCL inside the entry plug and his soul is absorbed into the EVA itself. This event is caused by the influence of the newly acquired organ which gives the EVA the ability to control its AT Field in ways previously impossible (such as offensively).
Blood Types
The phrase blood type refers to the individuality of a specified AT Field and is identified by colors. Some AT Fields are stronger than others - compare a human's with an Angel's and you'll get the idea. There are several colors, each (apparently) having its own characteristics.
Red: Used mainly by Angels. Shinji's blood type shifts from green to red during Third Impact.
Blue: Reserved for Angels and our girl Rei, blue is one of the more common colors.
Orange: Angel specific blood type.
Green: Human (enhanced by EVA) specific blood type.
Sepia: Human specific type. Sepia is the brown color seen in photo effects. This appears only during the Destrudo process.
AT Field Destruction and Interaction
Negative (destructive)
The destruction of an AT Field is a task impossible without another AT Field. Although neutralize would be a better description of the process, the word destroy does apply to a number of incidences. Along with destruction, there is another manner of negative AT Field interaction - nullification.
Neutralization
The neutralization of the Angel's AT Field is always the first priority during battle. This is necessary only when the Angel is generating a defensive field. The neutralization process occurs when two fields are in contact. For one field to neutralize the other, it must eliminate the phase space between the two. In other words, although both AT Fields are still active, they do not block the source of the each other - i.e.: the EVA and move in for the kill.
The best example of this is seen in the twelfth episode during the Tenth Angel's attack. The First EVA to arrive is Unit 01, which expands its own field and stops the Angel's freefall. Units 00 and 02 arrive seconds later and help neutralize the field.
Destruction
The destruction of an AT Field is not necessary to destroy the Angel. As seen in the twelfth episode, the AT Field remained active until the Angel was killed. After being neutralized, a field is susceptible to physical damage. In the twelfth episode, the field is cut open to expose the Angel's body. In the second episode flashback of the battle with the Third Angel, the AT Field is completely ripped apart after being neutralized. The nearly simultaneous destruction of an AT Field is observed in episode nineteen when Unit 01 hits the Fourteenth Angel with an offensive AT Field projection. The Angel's field remains solid for a second before shattering. It is interesting to note, however, that the Angel had already fallen before its AT Field did. This occurrence indicates that while part of the offensive projection interacted with the AT Field, another part was completely unaffected by its presence. This event (along with others) indicates that there is a third type of AT Field interaction.
Nullification
The nullification process is one of the rarer types of AT Field interaction. During nullification, an AT Field (or AT Field derivative) can pass through another AT Field without being affected. The first occurrence of this is seen in the above mentioned interaction between Unit 01's offensive projection and the Fourteenth Angel's defensive AT Field. Another example is the Fifteenth Angel's AT field based attack on Asuka's psyche that Unit 02's AT Field can't stop. A third occurrence of the nullification process appears during the battle with the Sixteenth Angel when the Angel passes unimpeded through Unit 00's AT Field and begins to invade the EVA's body.
AT Field nullification also occurs in another strange manner - the deconstruction of a human body. First observed when Shinji is dissolved into LCL, the true first occurrence of deconstruction was the accident that claimed Yui Ikari - breaking her body down and releasing her spirit to be absorbed into the EVA. The final and most massive deconstruction is the Instrumentality, in which the bodies of the entire human race are reverted to LCL. The Instrumentality is created by the Anti-AT Fields of the mass produced EVAs; by this, nullification is dependent upon certain characteristics held by an Anti-AT Field.
Positive (constructive)
There are only two times that the positive AT Field interaction is seen. The first is the formation of the Tree of Life by the nine mass produced EVAs and Unit 01. Their AT Fields complement one another and begin the Third Impact by creating a massing shockwave that pulls the Black Moon free of the Earth. The second time happens moments later when the nine EVAs, along with Lillith, combine their AT-Fields into one - creating the massive Anti-AT Field that starts Instrumentality.
Special AT Fields
Besides the standard AT Fields and Anti-AT Field, there are three other subcategories of AT Fields. These are the inverted, reversed, and personal field types.
Inverted
Seen only once, the inverted AT Field is an oddity as strange as the Angel who possessed it. Generated by the Twelfth Angel during the sixteenth episode, the inverted AT Field is a strange subclass of fields. The term inverted means that the field, rather than facing outwards, faces inwards. Think of the AT Field as a shield - it's nice to have, but it's of no use if you can't fire through it at your enemies. The standard AT Field is like this; keeping things out while allowing something on the interior to pass through. The inverted field reverses this by allowing objects on the outside to pass through while objects held inside the field cannot escape - which is precisely what happens to Unit 01. The inverted AT Field is also the secret to containing the Sea of Dirac - the bizarre high-energy realty of the Angels. Since nothing can pass from the inside of the Angel's body into the world outside, the surrounding area is safe from whatever effects the Sea could have on our reality. The effects caused by a lack of an inverted AT Field to contain the Sea are seen when the botched S2 activation experiment summons the Sea to swallow a large chunk of Nevada, NERV US second branch, and Unit 04 (episode seventeen).
Reversed
Like the inverted field, the reversed field appears only once in the series. Generated by Unit 00 during the attack of the Sixteenth Angel in the twenty-third episode, the reversed field is a suicide maneuver. After the Angel has infected both her EVA and her, Rei reverses her AT Field to keep the Angel away from Unit 01. The AT Field pulls the Angels into Unit 00 more and more, forcing further fusion between the EVA and the Angel. The plus side is that the Angel is contained, the down side is that EVA 00 and Rei are completely contaminated by the First Level Contact.
Personal
Although every living thing with a soul possesses an AT Field, only certain ones can utilize its full potential without the aid of peripherals (like EVAs). Only two individuals are seen generating AT Fields, and both do so at the same time. During the descent to Terminal Dogma, Kaworu defends himself against Unit 01's Prog Knife with an AT Field. He also generates a second AT Field that cuts off all sensor information to the Command Center. After landing in Terminal Dogma, Kaworu's second field is counteracted by the Rei's personal field. Since both individuals were of Angelic nature, it is questionable as to whether a full-blooded Lillim (human) could manifest their AT Field in a similar manner.
Whoo...anyway, tell me what you think about this and feel free to point out any errors.
