Hellmouth

The Hellmouth is a location on the Moon that refers to both an underground fortress constructed by the Hive and the area of the Moon's surface surrounding the massive pit that gives the fortress its name. It serves as the main staging ground for the Hive God Crota, Son of Oryx, and his forces for their invasion of Earth. The Hellmouth features an inner sanctum, gatehouse, and dungeons that are located in the depths of the fortress, imprisoning the Hive's most fearsome denizens.

Overview
The Hellmouth's many underground passages reach far and deep into the Moon; besides the main entrance through the Gatehouse, it also has tunnels connected to the Temple of Crota and Archer's Line. Within the Hellmouth itself is a labyrinth of chambers for various purposes; The World's Grave, containing the Hive's collective history and many of their secrets, the Chamber of Night, where the Hive perform profane rituals, the Summoning Pits where Phogoth, the Untamed is kept chained, the Shrine of Oryx where the Hive contact their mighty king, Oryx, the Taken King. In the deepest, darkest pit in the Hellmouth is a rupture leading to the Oversoul Throne, the throne world of Crota, Son of Oryx.

Two years after the Red War, the Hellmouth is still a prominent Hive Stronghold on the moon, now entirely under the guard of the Hidden Swarm instead of the Spawn of Crota. Parts of Hellmouth's structure seem to have been stripped apart, presumably to construct the Scarlet Keep.

History
The Hive are known to have infested the Moon for hundreds if not thousands of years. They would slaughter inhabitants of the Moon during the Collapse. After the Collapse, Hive forces of the Hidden Swarm, Spawn of Crota, and the Blood of Oryx led by Crota would conquer the Moon and fortified what would become the Hellmouth. Then, they would begin their plans for an invasion of Earth.

The City Age
During the City Age, Hive forces would arrive on Earth and occupy parts of the planet, including the Rusted Lands where the champions of the Traveler would first discover their presence. Legendary Hunter Rezyl Azzir would arrive on the Moon and confront the Wizard Xyor, the Unwed who prophesied that he would fall. After Rezyl succeeded in killing Xyor's consort, he took the Knight's chitin to adorn onto his gun Rose before he returned to the City.

The Great Disaster
After the Battle of Burning Lake, where the Hive's attack on Earth was repelled, the Consensus decided to launch a counterattack on the Moon despite the protests of Shaxx. An army of hundreds of Guardians would arrive on the Moon, but they were slaughtered by the Hive, now led by Crota in person. The Hope Eater would then retreat into the depths of the Hellmouth, in his Thone World, to recover his debts.

The First Hunt for Crota
Years later, a fireteam led by Great Disaster survivor Eriana-3, alongside Eris Morn, Omar Agah, Sai Mota, Vell Tarlowe, and exiled Warlock Toland infiltrated the Hellmouth to seek vengeance for the Great Disaster by slaying Crota. Though they succeed in destroying Crota's physical form, his followers and liutenants would hunt down the members of the fireteam. Only Eris survived, but lost her Ghost, while Toland became an Ascendant spirit. Eris survived in the Hellmouth for years and eventually escaped, seeking to take revenge on the Hive for the death of her fireteam.

A Guardian Rises
When a newly risen Guardian arrived on the Moon, they would travel to the Temple of Crota learning from a dead Ghost of the Hive's planned invasion of Earth. The Guardian would repeatedly infiltrate the Hive fortress, stealing data from The World's Grave, slaying the Swarm Princes with the Sword of Crota, which broke afterwards, and killed Sardok, Eye of Oryx, destroying the shrine of the Taken King in the process. The Siphon Witches of the Hidden Swarm began a ritual to drain the Light from a shard of the Traveler, but they would once again be stopped by The Guardian. Later, a fireteam would storm the Hellmouth, sent by the Vanguard to kill Phogoth, the Untamed.

The Dark Below
"Six of us went down into the pit. Only one crawled out. I am Eris the last. I have seen what the Hive call a God."

- Eris Morn

The disciples of Crota, led by his consort Omnigul, Will of Crota, would begin their plans for the their master's return. Eris Morn calls for assistance to stop the return of the Hope Eater. After the death of Sardon, Fist of Crota and failing to take control of one of Rasputin's war bunkers in the Cosmodrome, the Spawn of Crota had to hasten their plans for their lord's resurrection. They would successfully wake his soul, but The Guardian would infiltrate the ritual, killing the Wakers and destroying the crystal housing the spirit, stopping him from re-entering the physical realm. A team of Guardians would track down and kill Omnigul, and later a six Guardian Fireteam would raid Crota's Throne World, killing Ir Yût, the Deathsinger and bringing an end to the Son of Oryx.

The Taken War
After the death of Crota's father Oryx, the Taken King, along with his forces, would make his way to Sol to take revenge for the death of his son. To find a way into the depths of the Dreadnaught, the Guardian would infiltrate the Hellmouth again, to take a piece of the crystal that once held Crota's Soul, and then the Hope Eater's Throne World, to charge the crystal with his departing essence. The Guardian sneaks past the forces of the Hive, including the Deathsingers Ir Anûk, Ir Halak, and Ir Yût, where they were holding Crota's funeral, and stole a piece of the Prince's essence. This allowed the Guardian to successfully became Ascendant, and would go on to bring an end to the Taken King.

Later on, Malok, Pride of Oryx would escape to the Hellmouth after being driven from the Dreadnaught, and attempt to perfect a dark sorcery that would allow him to seize the Osmium Throne. A team of Guardians would intercept the Knight however, and slay it, putting an end to its ambitions.

SIVA Crisis
The Devil Splicers would descend into the fortress to take unborn Ogre eggs to experiment on with SIVA. A Guardian fireteam would be sent stop this, killing both the Fallen and the Hive abomination they attempted to enslave. Following the defeat of the Devil Splicers' leadership, Omnigul, Will of Crota would return and the Vanguard would task fireteams with killing her for good.

Rising from the Depths
Years later after the death of Oryx, Crota and most of the other high ranking Hive leadership, the Hive on the Moon were left scattered and leaderless. The daughters of Crota and Omnigul, Hashladûn, Besurith, Voshyr, and Kinox had now rejected the Sword Logic and couldn't imagine a world without their King. They began plans to take control of the Hidden Swarm and resurrect Oryx. However, a powerful champion known as Zulmak, Instrument of Torment became a strong candidate for leadership and a threat to the Daughters' plans. Later on, three siblings began a conspiracy to bring an end to the Daughters, the brother Akrazul, the Severed, and the Deathsinger sisters Azavath and Malkanth, the Deceiver. They would use a forbiddent ritual where Akrazul possessed Azavath's body, but the brother would go mad, killing his sister and many other powers champions, including Zulmak, before being killed by Ir Airâm, formerly Azavath, who had know possessed the body of Malkanth. Crota's daughters would be greeted by their great aunt Savathûn, the Witch Queen. She would convince the daughters to take power, and construct a new fortress to stand against the servants of the Sky. She would also give them the essence of Zulmak, so that he could be raised as a puppet champion. The daughters would succeed in rallying the Hidden Swarm under their leadership, and would construct the Scarlet Keep. However, unknown to them this was a trick of the Witch Queen, as she was the one that influenced the three siblings, and placed Ir Airâm's essence in her sister's body with the promise she would lead the Deathsinger's choir. All this was done so that the Guardians would come to slay the daughters of Crota, as the Witch Queen believed that bloodline had run its course.

The Haunting of the Moon
When Eris Morn accidentally disturbed the Lunar Pyramid, she unleashed its influence over the Moon, awakening the Nightmares. The Daughters of Crota would use the Cryptoglyphs to summon, command, and protect themselves against the Nightmares. After killing Hashladûn in the Scarlet Keep, and learning about the Cryptoglyph, Eris Morn would send the Guardian to retrieve one of them. The Guardian would enter the Hellmouth, kill Besurith, and take the Cryptoglyph.

The Hellmouth would serve as the lair for most of the Greater Nightmares that appeared in this conflict, with Guardian teams constantly hunting them by passing through and within the area.

Toland, the Shattered would later guide the Guardian in the depths of the pit again, to kill Ir Airâm and her entire Deathsinger coven, and bind their essence into the Deathbringer.

With the destruction of the Sol Inherent, the Undying Mind would return, and direct the Sol Divisive to invade the Moon, including the Hellmouth. The Vanguard would succeed in destroying every copy of the Undying Mind, bringing an end to it for good, though forces of the Divisive still prowl the lunar battlefields.

Rescuing Osiris
When the main force of Xivu Arath's invasion arrived in the Sol System, she would send her High Celebrant into the Hellmouth to gain the alliance of the remaining children of Crota. The Warlock Osiris infiltrates this meeting, and slays all the leaders of the Swarm, but his recklessness forces his Ghost Sagira to sacrifice herself, rendering him Lightless. He would then run into Savathûn, who stole his form and wisked him away. Savathûn, now disguised as Osiris, would call out to the Vanguard for help. The Guardian would infiltrate the Hellmouth once more, fighting their way through the forces of the God of War, and making their way to Savathûn. The Witch Queen would be attacked by a Wrathborn Knight, but would be saved by the resurrected Uldren Sov, now known as The Crow.

Points of interest
The outer surface of the Hellmouth covers a wide area, including a platform overlooking the pit and a small moonbase hidden away in the rocks. Public Events, resource nodes, and patrol beacons can only be found on the surface of the Hellmouth, not within.
 * Destiny 2
 * Lost Sector
 * K1 Crew Quarters
 * VIP Patrol
 * Nightmare of Talgoth, Soul Smasher
 * World Events
 * High-Value Targets
 * Fissure Ogre
 * Ransack Servitor
 * Enemies move against each other (Fallen vs Hive)
 * Fallen Scavengers
 * Roving Pikes
 * Manifested Nightmare
 * Other
 * The Nightmare of Jaxx, Claw of Xivu Arath appears in this area every four weeks.
 * The Wealthkeeper's chest can appear in a number of spots in this area.
 * A Trove Guardian can appear in this area.
 * A Rabbit Statue can be found in the area.

Trivia

 * From a design standpoint, the Hellmouth is meant to evoke feelings of scale, menace, mystery, darkness, evil, strength, militarism, and the exotic without coming across as being too alien. Its imagery is meant to invoke feelings of Medieval/Gothic architecture.
 * There is a bug were, if one has a Sparrow that allows tricks you can cross the Hellmouth by going near the entrance of the temple that leads to the Summoning Pits and The World's Grave, jumping off of an angled rock near the Hellmouth, spinning at the right time, jumping off at the right time, and then Fist of Havocing once one starts to fall, and a whole lotta luck.

List of appearances

 * Destiny
 * The Dark Below
 * Rise of Iron
 * Destiny 2
 * Forsaken
 * Season of Opulence
 * Shadowkeep
 * Season of the Undying
 * Season of the Hunt