Seven Hells

The seven hells are the demon realms of eternal torment and darkness in the world of Dota 2.

Description
According to Terrorblade, hell is a sieve, in contrast to heaven which is a locked box. Perhaps he's saying heaven is very exclusive compared to hell, since the former only accepts the souls that have been utterly purified of any evil, just like a locked box where nothing may even seep inside. Whereas hell will easily accept souls who possess any evil in them in spite of what good they hold, since it is only their sin that matters; like a sieve with its pores, allowing anything to go through. With their differences in accessibility, Terrorblade might also be saying heaven is pure and clean while hell is impure and corrupt, hence the locked box and sieve metaphor.

Terrorblade also mentions seven bells that ring when he dies. Perhaps these bells correspond with each layer of the seven hells and these knells toll upon a demon's death.

Between each layer of hell is a membrane that separates them from each other and bars anyone who isn't Doom from crossing between the seven Infernal Regions.

When accessing hell one way or another, a great wail of suffering and anger can be heard, a wretched sound probably produced by the damned reacting to their torment and woe.

In defiance of the laws of nature, hellfire burns forever that those afflicted will suffer eternal torment. Annihilating the body, hellfire is as eternal as the soul that it burns.

Layers of hell
Despite being a place of utter darkness, Doom says the hottest hell is very bright because of its intense hellfire. Supporting this is a mention of "infernal light" in accessing hell.

First Hell
Nothing is known about the first hell.

Second Hell
Nothing is also known about the second hell.

Third Hell
Zilch.

Fourth Hell
Nada.

Fifth Hell
A row of overlapping armor plates for Doom's tail was forged here.

Sixth Hell
Maraxiform originates from the sixth hell. This is the place of Clinkz's damnation should he lose the war of the Ancients.

Tassets cast of finest steel were hardened in the sixth hell's deepest pits, a piece of armor destined for Doom's belly.

Seventh Hell
Doom wears a pair of runed bracers that were forged in the cauldron of the deepest hell. Those who are slain by Doom himself are sent to the lowest hell for their damnation.

Other Hells
The Abysm is an inscrutable and unfathomable abyss where the souls harvested by Nevermore dwell in for eternity.

Little is known about the sixty-four planes of the Lesser Hells, besides it being a place of eternal damnation and suffering just like any other hell.

Not much is known about the Outer Hells, besides it being the ' abode whence Demnok Lannik plucked their souls from.

In Dota: Dragon's Blood
The seven hells exists in the cosmos of Dragon's Blood. Like all realms, the seven hells' existence is supported by the eight Pillars of Creation.

Such demonic realms are also included in the in-universe expressions of Dragon's Blood, replacing real-life expressions that use the word “hell” in them.

In an attempt to resist Luna's interrogation, an injured Coedwen curses her to burn in the fourth hell. Other than that, nothing is known about the fourth hell.

Jarl mentions the fifth hell when he curses the tight and itchy armor he's wearing, likening its itchiness to said hell. Besides this, not much is known about the fifth hell.

Heroes
is the ultimate Demon Lord and the sovereign of all hells. As such, he alone has the ability to cross between the seven hells unimpeded and unrestrained. Second only to Doom himself, the is the penultimate Demon Lord and may have some dominion over some parts of the Seven Hells. Nevermore the is the least of the Demon Lords. However, he has a seat in the Court of Ristul with the lords Vrogros and B'Kor to gain clout in the umbral plane. is a criminal demon who broke every law of the seven Infernal Regions, earning him the fear of other demons and an incarceration to Foulfell.
 * Because of Doom's absolute authority over the seven hells, he also embodies the seven hells when he represents it, its hunger (possibly for souls), and its fury.
 * It is said that Doom carries his own hell with him wherever he goes. Most of his powers draw upon the fires of Hell to incinerate and torture those who cross him.
 * Lucifer causes beneath his cloven feet as the hellfire that sustains him laps in his wake, burning anyone in his dreaded presence.
 * shares the same fire branding that was bestowed upon him at the time of his exile from the light, annihilating foes and torching their soul.
 * The Fallen One bears away souls on the tip of his, which also shares the same fire branding placed upon his wings that once bound him to the light.
 * Doom's infernal sword glows ever hot with the heat of all the seven hells, its heat continuously forging the blade.
 * Doom owns a thorny sword that is said to be all-seeing in the burning pits of the stygian waste.
 * The once luminous Lucifer met his by having his wings branded with flame, stripping him of the tethers that bound him to the light and exiling him from it.
 * Those who have met their doom in the Fallen One's hands will fall to the seven hells to suffer, perhaps ending up in the deepest layer of hell for their damnation.
 * Doom falls to the seven hells when he dies where he goes to the furnace. From there, he is brought back to life, ready to resume his path of destruction once more.
 * Most of Doom's armor was forged in hell, such as his pauldrons of rancid steel and demon hide, tail plates, tassets of finest steel, and cauldron-forged bracers.
 * The place that his sends his victims to is said to be his hell or omoz, a place of utter darkness inside and deceptive illusions once they leave.
 * When Shadow Demon dies, he falls to the abyss where he is welcomed, a place of “darkness within darkness” that is possibly his abode.
 * Naturally as a selfish demon, the greedy Nevermore seeks to usurp Doom's dominion over the seventh hell for some reason besides his hunger for power.
 * Nevermore was once kept in Doom's hell and seems to have escaped it ever since. He asserts to Doom that he will never return to him and his pit in an act of defiance.
 * He can damn others after he has killed them, like sending Nevermore to the lowest hell, trying to keep Lion in hell, and damning Warlock for other mages to summon.
 * When he dies, his soul descends to and returns to hell, like most demons. But unlike most demons, hell rejects his presence, sending him away and back to life.

Races
Demons are the native inhabitants of the seven hells. The heat of Hell courses through their veins, which continues to flow through any weapon they dare to wield.

Artifacts
Broken into a thousand pieces in the battle of Heaven's Gate, the Blade of Worlds' largest shard was smuggled back to Hell's forges to be reformed into the Demon Shard sword.

Heroes
wields a blade aptly named "Nightmare Blade" that was spat out from the hells. When swung in battle, Axe will later find his dreams haunted by the blade's victims.

owns an infernal, timeless blade that's meant to snuff out the Light wherever he may find it. Perhaps its infernal quality has something to do with hell itself.

is best known for slaying Maraxiform of Sixth Hell, only to live as a tortured soul from an untimely event when his eternal immolation was preserved by Sutherex's reward. Empowered by Qwyth's hellbound blades, the is infused with hell's depthless power. Although she's not a demon, she is as corrupted as one nevertheless, fighting for all seven hells. Those she slays are condemned to suffer in every hell. Descending into hell for revenge, killed his demon partner who betrayed him before taking the traitor's left hand for himself, grafting it to his body for its stygian power. is a psychopomp who only seems to bring the dead in her wake to the seven hells. She also mentions the seven hells as an expression of happiness.
 * The duality of Clinkz's powers involves his vital immortality spell and Maraxiform's hellfire. Some of his abilities draw terrible power from the latter, but are put to honorable use.
 * From his ever burning soul, Clinkz's give his foes a death by impaling hellfire, a fate he reserves for those who make threats to the Hoven.
 * With a puff of fire and smoke, Maraxiform's flames hide Clinkz in a that allows him to sneak up on foes or disengage from unfavorable fights.
 * Just as Maraxiform's fire ever burns his soul, Clinkz constantly escapes Maraxiform in death. But the time may come when the rift to Sixth Hell will come for him...
 * The Bone Fletcher owns a bow said to have been brought back from hell itself. With this stygian bow in hand, his enemies will feel his searing fury.
 * Long before his corruption, it's implied Lion had already mastered the powers of Hell through the aptly named Demon Witch tradition of sorcery.
 * In order to harness the powers of hell, Lion wields a feared and malicious scepter symbolizing hell. Possessing an incubus' skin is proof of his mastery over the inferno.
 * With his third eye, Lion peers beyond reality and clearly sees the vile powers beyond. With this power, he stands in defiance of powers both seen and unseen.
 * As expected from consorting with demons, Lion is beyond any hope or redemption, allowing him to wear a ruby ring that would've burned his soul if he was otherwise.
 * Lion wields several spells in his arcane repertoire that draw upon the dark power of Hell to ensure his victory in battle.
 * Out of a fissure from hell bursts a row of that impales his enemies, a devastating result of Lion exercising his demonic covenant.
 * On the left hand of the Demon Witch was the betrayer's, capable of flooding his foes with malefic power to shred them into pieces.
 * Anyone who crosses Lion will be damned to a one-way trip to hell to suffer forever.  Additionally, he tells his fallen to let Hell know that it was him who sent them there.
 * Lion may go to hell in death, but not for long. By his sheer rage, he escapes hell to live again.  Having been there many times, he is sated with all of its torments.
 * In another continuity, Lion assumed the mantle of Hell's own Ambassador. A grateful demon populace bestowed him a fitting collar to express his position, while evil epaulets of hell plucked from the stygian pits complimented his collar. When speaking for Hell, Lion carries the Strifemaul to emphasize the important points of his arguments.
 * Lion wields a wand fashioned from a lurid thorn that he plucked from the pits of hell.
 * Lion claims he does not fear Hell, but rather Hell fears him. He is hated by the Court of Ristul and hunted by them for the hand he stole from his demon partner.

owns a massive blade long rumored to exist that sends anyone whose flesh is torn by its razor sharp edge straight into Hell.

calls upon his “hellish lineage” to unleash a. It seems this fire may come from a being of ethereal flame that attacked him in the abyss.

The 's deathless existence prevents him from permanently passing into all sorts of afterlife, including the hells that discharge him when he dies.

It is up to to ensure that all untethered souls remain in their respective heavens and hells, retrieving any fugitive spirits whenever they escape their afterlife.

sought to collect the shards of the shattered prison plane Foulfell to extend his rule to the Infernal Regions by imprisoning demon souls in these fragments.

Gods
A poem of Muerta's origins shows that can damn not only those who have simply died, but also those who are about to die and have lost to him in a game of souls.

World
The cold Narrow Maze is the universal pathway to all sorts of afterlife. At the labyrinth's end, luminous exits lead to blissful heavens, while dark endless pits lead straight to hell.

Arts and Traditions
The Demon Witch tradition of sorcery is a rare art of manipulating the power of the hell and the demons within it.

Items
Although it was said to be forged in the Nether Reaches, later lore says that the came from hell.