The air before user becomes a shimmering curtain that blocks all that opposes it. It is a kind of psychokinetic wall that is as much a projection of the force of ones personality as it is an energy construct
The Absolute Territory Field or AT field for short is a barrier that the Angels can generate to protect themselves. AT fields typically take the shape of an octagon or a hexagon and are usually orange in color. In some cases, AT fields have appeared in other colors and hues, such as a pastel purple, or red. Not much is known about these barriers, although, according to Kaworu Nagisa the AT fields are the barriers that protect your space and give you form. This statement is repeated in The End of Evangelion. It is also believed that these barriers can be projected by any being that has a soul. The strength of AT fields produced varies between angels, for example the angels Zeruel and Ramiel posses extremely powerful AT fields while Matariel's AT field was very weak. The strength of Evangelion units' AT fields depends upon the synchronization level of the pilot, and the strength setting used at the time. Eva pilots can control the strength of the AT field from their entry plug.