The Underworld, a bottomless pit and a realm of shadows where demons and the fallens gathered.
Humans believed that it is an afterlife place where evil souls and sinners pay the penalty for their crimes. It is a place where eternal suffering and unending punishments for the wicked after death.
Some believed it was a humongous, smoky land shrouded by fire, filled with an indescribable and suffocating smell where demons and monsters lived. But for them, the Underworld was simply their home.
Demons are supernatural entities associated with evil or malevolent spirits that influence humans to act viciously.
Monsters are creatures of the Underworld, usually described as scary and with hideous appearances.
There were seven gates of the Underworld, and Acharon, the river of the dead, was the fastest way to go to Terra.
The Underworld has nine layers. Semel, Cordus, Tertius, Poena, Gelum, Perfidia, Caligo, Letalia and Altum.
The oldest demon princes guard the eight layers while the Demon King itself defends Altum.
Zuriel, Amaris' uncle, was considered one of the strongest demon princes and previous ruler and guardian of Semel, the first layer of the Underworld. Now, it is guarded by one of her sons, Igdred.
Semel has infinite size, a barren land destroyed by endless battles. It is the only passage to the deeper layers of hell. Acts as the arrival point of all outsiders. It is a desolate, stony wasteland, shattered by rivers of blood and plagued with multitudes of biting flies. The guests and invaders of the demon realm will have to go through Semel and face Igdred.
The next layer was called Cordus. It was a flat, empty plane with little more than black, stagnant rivers extending thousands of miles until it reached some rolling hills. A spiral labyrinth of peaks and gorges, rich with iron ore. All routes in the plane of Cordus were entirely made of iron defended by bastions made into the flanks of craggy mountains.
In the epicenter of this plane was the Iron City of Cordus. The foul rivers beamed from a trench large enough to be called a lake shrouding the Iron City. The walls of the structures and the stones of the streets glistened by the faint red of hot iron; a short skin contact would result in severe burns. Astreth, Zuriel's cousin, guarded the second layer of hell.
Tertius, the third layer of the Underworld, guarded by Ellmin, was described as an endless marsh of horrendous pollution, rotting bodies, and decaying bog, constantly soaked by rain, sleet, and hail storms. The fluid, bone-strewn, disease-ridden wetland made movement very tough and occasionally broken by twisting volcanic rock ridges.
The third layer was a realm depicted as a vast but low-vaulted cavern attached to Cordus. Oily water oozed through the roof of the cave and rained down upon swamplands, deserts of mud, and seeping black soil, potholed by rippling fumaroles and dirt geysers.
The atmospheres rain down the acid, and large craters wait to gobble the unwary. At its center rises the muddy walls of Cordia Palace, home of Ellmin, the ruler of Tertius. He is the banker of the Nine Hells, frugal and ravenous. He is the only demon prince to adore coins and anima, and he stashes his fortune deep in his domain.
Azalea wasn't sure who guarded the following layers of the Underworld.
Phoena, the fourth layer of the Underworld, most resembled the stereotype of a fiery world of endless damnation, loaded with active volcanoes, rivers of liquid flames, molten rocks, ash hills, smoking craters, severe heat, wracked by earthquakes and tremors.
The city of Phoena was the seat of power in this domain, built with hardened magma, obsidian, and crystal in the caldera of an expired volcano which provided visitors some security from the elemental surroundings found throughout the rest of the plane.
Gelum, the fifth layer, was the complete opposite of Phoena. It was either a bottomless ocean covered by an ice sheet or a frosty sea salted with enormous icebergs buried in cavern miles below Cordus and Phoena. A realm of freezing fire and bitter cold. The sky splits with lightning, and a frozen ocean envelops the layer. It is also home to numerous dangerous beasts.
Perfidia, the sixth layer of the Underworld, was a perpetually slanted mountainside, serving as the nine layers' jail and torture chambers. Those found guilty in Phoena were sent here for retribution. While structures built into the slope, boulders, and landslides are an ongoing threat, wreaking mayhem on the terrain.
The seventh layer, Caligo, houses all the records of the Underworld. Spiraling belowground mazes contain every agreement signed or pact struck, designed in a way that only the protector and his minions can locate anything. It is also a bleak space of wrecked cityscape, flush with ruin and decay.
Letalia was also a land of bitter cold like Gelum. But the eighth layer functions a much more vital role in the Underworld. Basically, it is one huge laboratory nestled in the ice created to conduct impenetrable experiments.
Altum, the ninth layer, home of the Demon King itself. Amaris' father, Phelan, was the son of Asmodeus, the former ruler of this barren place. He was the one who sent Phelan to the human realm.
Now, Altum was ruled by Zuriel, the strongest demon of the Underworld. Barren of design movement covered with shaded pits striped with defenses lodging his faithful pit devil generals and their armies.
He lived in the tower of Alsheem, the Citadel of the Underworld. It was large enough to shelter millions of devils, Zuriel's vast army, which increased in number every time he produced a driblet of blood.
Asmodeus itself designed Alsheem, so it was impossible to collapse or get ruined. The primary structure was made of stone, and Baatorian green steel, a lighter but stiffer than ordinary metal, extends in an X-shape for miles along with the foundations of both gullies.
Below Altum was the second part of the Underworld, Tartarus.