Dark War

The Dark War (暗黒大戦 Ankoku Taisen), also known as the First War of Ars Magus (第一次魔道対戦 Daiichiji Madō Taisen), was a world-wide conflict in which humanity, vampires, beastkin, demi-humans, and Kaka fought against the Black Beast. It started on January 1st, 2100AD and ended 10 years later on January 1st, 2110.

The brutality of the Dark War led to the death of over half the world's population as well as the development of Ars Magus and the Hierarchical Cities. Scars left from the war are still felt across the world even 90 years after its conclusion.

Information
Several events prelude the beginning of the Dark War. Scientists Relius Clover and Shuichiro Ayatsuki partnered together with Yuuki Terumi to develop a Kusanagi which was to be used to kill The Origin and the Amaterasu Unit. During this time, Shuichiro developed the Kushinada's Lynchpin should their experiment fail. On December 31st, 2099AD, the experiment failed and a Black Beast was born instead within the First District - it killed Terumi's current host, devoured Relius, and grievously injured Shuichiro before escaping to the outside world. This is what the scientists and the world at the time believed. In reality, the Black Beast was actually a fused Nu-13 and Ragna the Bloodedge that were sent back in time from December 31st, 2199AD to just before the Looping World begun.

The Black Beast's first recorded appearance was in Kantō, Japan, and it annihilated the country's population. The United Nations held an international summit meeting shortly afterwards and concluded that the only solution that they knew was to obliterate the country using a . These attacks failed to even scratch the Beast's hide and it went on to spread across the world. Before the nuclear strikes, some of the population was evacuated, including a tribe of cat-type beastkin that included Jubei, Tomonori, and Munefuyu. Jubei later allowed an unknown country to use his genes to develop the Kaka in an attempt to combat the Beast - the country was one of Beast's many victims.

The Magister's City of Ishana was untouched by the Beast since no seithr entered the city's atmosphere. A woman called Konoe Mercury, the oldest daughter of Shuichiro, was appointed Nine of the Ten Sages; she held absolute authority over matters concerning the Black Beast and Dark War in Ishana. Clavis Alucard, the head of the Alucard Clan was aware of a student in Ishana called Kazuma Kval, who was designed as a vessel for Terumi. The failures of Nine, Clavis, Tomonori, and Clavis' butler Valkenhayn R. Hellsing led to the resurrection of Terumi in 2106AD.

Celica A. Mercury, the youngest daughter of Shuichiro, ventured to Japan to find her father in 2106AD. In February of 2200, Rachel Alucard sent Ragna back in time to the Dark War where he lost his memories and met Celica. The two, alongside Jubei, Nine, and Trinity, found the First District and watched Shuichiro die after introducing them to the Kushinada's Lynchpin. The group refused to use it since it required Celica's sacrifice, and they were attacked by the Black Beast itself. Ragna threw himself into the Beast and managed to stall it for one year as he fought against a version of Nu that resided within it. It was around this time that Clavis passed away, making Rachel the new head of the Alucard Clan.

Humanity and the world were given one year to find a way to develop something that could combat the Black Beast and end the war. Nine had already begun development on the fusion of magic and science before the war, and focused her efforts.

When the Black Beast was defeated, it began to deflate, becoming the size and shape of a man - it was the Ragna that had become the Beast after being sent back in time. Hakumen personally saw to the death of the Beast, walking up to it and decapitating it with Ookami.

Aftermath
The seithr that was dispelled from the Black Beast's body flooded the entire world, suffocating areas in a lower altitude. Flora and fauna caught in the seithr were either killed or mutated; the immediate aftermath of the Dark War was arguably as destructive as the war itself. The Earth's ecosystem was destroyed, giving birth to new and never seen before creatures. The OLN merged with the Mage's Guild to become the Novus Orbis Librarium, which established the vigilante system. Vigilantes were used to help secure the deadly world for the remnants of society.

Almost immediately following the aftermath of the war, Celica became a nun. Jubei and Nine erected Celica A. Mercury's Church over the site where the Black Beast died. Nine and Jubei were later married and the church and had a child together - Kokonoe. A short time later, Nine realised the truth of Looping World and the Prime Field War, so begun creation on the 11th Nox Nyctores, the Corpus Sepulcro: Requiem. Terumi later destroyed this happiness as Kazuma convinced Trinity to unbind the Mind Eater that had been applied on them. Terumi threw Nine into the Boundary, citing her as knowing too much, and then threw Trinity in after her; Trinity, however, sealed her soul into Muchourin before her body's demise.

Both Jubei and Hakumen later fought against Terumi. Hakumen sacrificed himself to drag Terumi into the Boundary, killing Kazuma, and leaving Jubei and Valkenhayn as the only surviving members of the Six Heroes. Valkenhayn left society to tend to the Alucard Castle as Rachel went into a deep slumber, but remained in contact with Jubei.

Humanity, beastkin, and demi-humans moved onto the mountaintops of the world where the seithr had not settled. Using the basis of Ishana and Ars Magus, society created the Hierarchical Cities, large NOL-governed cities with artificial environments designed for the remaining civilization to flourish. Other cities also survived the war, such as Shanghai, while others created cities far from the NOL's grasp. Before having been thrown into the Boundary, Nine had released the cores of some of the Nox Nyctores, sealing Nirvana underneath the 4th Hierarchical City of Naobi.

Society greatly changed after the war. Although beastkin and demi-humans were accepted into human society, they were treated as less than second-class citizens - combined with a growing use of people who struggled to use Ars Magus over those who could, the new society ruled over by the NOL and their strict governing over Grimoires led to a growing friction between commoners and officials.

Over time, certain parts of the world before the Dark War were forgotten. The United Nations, Japan, and nuclear weapons were largely forgotten by a society that came to heavily rely on Ars Magus. This led to the birth of Sector Seven as they remained true to science. The Kaka were also forgotten largely by society, being dumped into the bottom of the 13th Hierarchical City of Kagutsuchi. Sorcery, magic, the Mage's Guild, and the Ten Sages were also forgotten by society, and very few could use the two aforementioned arts; the availability of alchemy, however, is debatable.

Dark War
''A war to defeat the 'Black Beast,' which appeared in Japan on January 1, 2100. It continued until January 1, 2110.''

''During the 10 years of fighting, about half of humanity was wiped out. Because it was the first war whee 'Ars Magus' was used as a weapon, it is also called the 'First War of Ars Magus.'''

First War of Ars Magus
''Another name for the 'Dark War' which the Six Heroes fought in, lasting from January 1, 2100 TO January 1, 2110. It is called by this name because it was the first war where humanity used 'Ars Magus' as a weapon.''

Nuclear Attack
Measures the leaders of many nations took to defeat the 'Black Beast.' They used an enormous number of nuclear weapons, but they could not defeat the 'Black Beast.' The crater at ground zero contains a massive amount of radiation, making it impossible to enter without protective gear.