Appears in Episode: 22
In Episode 22, as Evangelion Unit-00 descends into Terminal Dogma to recover the Lance of Longinus to use against Arael, the Fifteenth Angel, it is said to have passed through the sixth Malebolge Trench. This is a reference to The Divine Comedy, a three-part Italian epic poem written by Dante Alighieri between 1308 and 1321.
The Divine Comedy (first part of which is also famously known as Dante's Inferno), is considered among the greatest literary works of the Middle Ages, and depicts a first-person account of Hell. In Dante’s version of Hell, categories of sin are punished in different circles, with the depth of the circle (and placement within that circle) symbolic of the amount of punishment to be inflicted. Sinners placed in the upper circles of Hell are given relatively minor punishments, while sinners in the depths of Hell endure far greater torments. As the eighth out of nine circles, Malebolge is one of the worst places in Hell to be, and involves sins such as deliberate deceit, fraud, or treachery.
Malebolge itself is a large, funnel-shaped cavern divided into ten concentric circular trenches or ditches. Long causeway bridges run from the outer circumference of Malebolge to its center, pictured as spokes on a wheel. At the center of Malebolge is the ninth and final circle of Hell, Cocytus (where Lucifer/Satan is imprisoned in a frozen lake). In other words, each Malebolge Trench is a level of Malebolge designated for a certain type of sin. The lower the level, the more severe the sin. The ten trenches are:
How does all this relate to Evangelion? There are several interpretations: