Core
A core (コア) is a red, spherical organ possessed by Angels and Evangelions. It uniformily serves as a container for the soul and, in Angels and some Evas, contains the S² Engine, as well. The core is (typically) the only vital point of Angels and Evas; unless it is sufficiently damaged, these entities can receive inordinate amounts of damage without truly dying.
In humanoids such as Adam, the Evas, and Sachiel -- and even Zeruel and Israfel -- the core lays exposed in the solar plexus region. (Lilith, alternatively, has no exposed core. Being outside of Adam's "family", she may not possess one at all.) The organ is positioned variously in other Angels. Examples:
- Shamshel: "Throat" region, exposed
- Ramiel: Centralized location, internal (never seen)
- Gaghiel: Back of mouth, visible with jaws open
- Sahaquiel: Center of "eye", exposed
- Leliel: Beneath ultra-flat "shadow", hidden
- Arael: Between "brachial" wings, free-floating
Leliel's unusual nature results in its core appearing flat (rather than spherical) within three-dimensional space. Ireul presents another odd case in being a collection of many microscopic entities: Is there one "shared" core, or does each individual possess its own? The nature of the cores possessed by the amorphous Bardiel and Armisael is also unknown.
For Yui and Kyoko's Contact Experiments and Eva piloting, the ventral end of the Entry Plug is inserted into the core. According to preparations made prior to Yui's Contact Experiment, a cylindrical cavity is excavated to permit the accomodation of the plug [21']. Eva cores also seem to generate their own supply of LCL [20, 23', 26'].
Eva-01 uniquely possesses two to four small core-like structures in addition to her main core.
At Second Impact, a black circle or ellipse appears in Adam's solar plexus region, apparently smaller in size than the core itself [OP, 12]. Possibly related, a dark circle (sphere?) manifests within Eva-01's core shortly before she fuses with the Spear of Longinus [26'].
While the characters consistently refer to the core as "koa" ("core"), the term koukyuu (光球) is sometimes observed in print. Koukyuu means "photosphere" ("a sphere of light or radiance") and is apparently in reference to the core's luminescent properties.
