GENERAL
Hell (地獄, Jigoku; Viz: "The Underworld") is the place where Hollows are sent if they were wicked when they were alive.
Overview
The Zanpakutō of a Shinigami can only cleanse spirits of the sins they committed as Hollows. If the spirit committed heinous crimes as a Human, it will not be sent to Soul Society, but through the Gates of Hell.
When Ichigo Kurosaki defeated the Hollow Shrieker, he did so by slashing Shrieker's Hollow mask. The Gates appear to be formed from energy or light which emerges from the wound. The Gates of Hell (地獄の門, Jigoku no Mon) are chained shut and adorned with the bandaged head and torso of a skeleton on each door. The arms of both skeletons are positioned at an angle to pull the gates open when it is summoned.
On the inside, the Gates appear to be prevented from opening fully by two thick ropes with charms attached to them. The face and left arm of a large demonic creature can be seen behind the Gates. It has armor plating on its upper arm and it wields a blade. Its left arm and face are covered in tattoos resembling tribal markings. The demon skewers the Hollow entering Hell with its blade, and pulls it through the Gates, while laughing. The Gates then close and the entire structure cracks and crumbles into nothing.
Effect Upon Hollowfication
Kokutō explains that the unique environment of Hell also has an adverse effect on individuals that possess Hollow-like abilities. While the extent to which is unknown, Hell's influence is powerful enough to coax Ichigo Kurosaki into inadvertently summoning his Hollow mask to defeat a Kushanāda. Kokutō also confirms that if Ichigo lets his guard down whilst fighting in Hell, his Hollow powers will manifest and take over his body. This happens on two separate occasions, wherein his inner Hollow completely takes over his body in Hell.
The First Level
First Level: The First Level of Hell features a multitude of white blocks floating in mid-air among a series of blue pathways. It is on this level that many of the dejected Togabito reside, having given up on resistance. Renji Abarai commented that the First Level of Hell has Reiatsu so strangled that people with normal Reiatsu would go insane. This level is where the majority of Kushanāda patrol frequently, in order to prey upon the weaker Togabito. At the edge of the blue pathway is a gaping abyss, through which the next level can be accessed.
The Second Level
Second Level: The Second Level of Hell is mostly composed of a large body of water. Within this large expanse of water, are a multitude of stone water lilies, in the center of which lies a pierced skeleton of a Kushanāda. It is on this level that Ichigo Kurosaki and his friends initially battle with the Togabito in Hell. The body of water can also be navigated through, and ultimately leads to the third level.
The Third Level
Third Level: The Third Level of Hell is a rocky, barren landscape with various craters in which yellow lava forms. It is here that Szayelaporro Granz and Aaroniero Arruruerie battled with Shuren and his comrades. Ichigo and Kokutō navigate through this area to reach Shuren's base at the lowermost level of Hell. Taikon, Gunjō, and Garogai are all defeated on this level. After the rocky landscape is cleared, there is a narrow passageway lit with the dim lighting from various shrines.
The Fourth Level
Fourth Level: The Fourth Level of Hell starts off with a hilly area in which there are a multitude of small domes jutting out of the ground. From the opening in the face of a cliff, a thundering waterfall with the yellow lava rains down around it. The sand which emits trace amounts of Reiatsu is comprised of the crushed bones of millions of Togabito, who turned to ash due to the hopelessness of their predicament. This section then crosses over into a giant skeleton resembling the ones which make up the Gates of Hell. This overlooks a pit of lava, which has the ability to resurrect killed Togabito. Around the skeletal structure, is a series of pillars and a set of stone fingers.
The Lowermost Level
Lowermost Level: The Lowermost Level of Hell is composed of a black landscape, with many irregular columns covered in veins of lava jutting out from the ground. The Kushanāda are capable of materializing from within these lava columns. This level was where Kokutō was imprisoned in Hell, and also where he subsequently awoke after witnessing Ichigo's Hollowfication. Lightning strikes are a frequent occurrence here. There are also withered trees composed of bones littered across the landscape, from which Kokutō hangs the bodies of Lieutenant Renji Abarai and Uryū Ishida for Ichigo to see.
