Herrscher of the Corruption/Synopsis

Synopsis of the Youkai Apocalyptic virus Herrscher of the Corruption from Guns Girl Z (Houkai Gakuen 2) and its popular sequel Honkai Impact 3rd

Guns Girl Z - Old World
Herrscher of the Erosion, or also known as the 12th Herrscher, was a sentient self-aware virus that was fused with Houkai energy and gained free will to act and think by herself, which infected humans and animals and turned them into zombies.

The year that came to exist is unknown but it's expected she was born during the rampage of God Kiana, also known as the Last Herrscher of the Old World, who brought the end of mankind and destroyed the world. After the Herrscher of the Erosion gained freedom to think and act by herself, the disease immediately considered herself to be superior and saw all living beings as her playthings and deemed them to be unnecessary to her new world she is going to create

The virus then infected a little innocent girl known as Higokumaru and used her as a vessel to spread one of mankind's most deadly plagues that killed 90,000,000 people in just a few months. When the innocent girl was discovered to be the host of the disease, the now Herrscher of the Erosion used her energy to bring the army of Fire Moth straight at her, resulting in the innocent girl being tortured by scientists to discover a cure for the plague and then executed in cold-blood when they considered her to be too dangerous to be kept alive.

Once her vessel was was killed, the Herrscher merged her mind with Higokumaru's and manipulated her hatred to turn her into mankind's deadliest enemy. The virus quickly left Higokumaru's body and infected all civilians in the North Asia, turning half of China's population into zombies and hacked into America and Asia's nuclear bases, launching nuclear missiles of Fire Moth and destroying half of the world, killing billions more just to create her own Plague Kingdom.

At some point, the Fire Moth captured her and had Professor Mei sealing the Herrscher inside of a Purple Box full of anti-Houkai energy, where Herrscher of the Erosion would be kept sealed for 49,500 years alongside her vessel Higokumaru.

Medieval Era
49,500 years later after God Kiana/Sirin reseted the world, the Herrscher of the Erosion continued locked inside of the Purple Box until one day in the year of 1490 D.C., the organization Shicksal (Entropy) found the Purple Box and began to experiment on it in an attempt to use its majestic power in a weapon against the Houkai beasts that were wreaking havoc the continent of Europe, leaving entire villages destroyed.

However, the experiment resulted in the opening of the Purple Box, ensuring the freedom of the Herrscher of the Erosion in the New World. Taken by hatred, Higokumaru allowed Herrscher of the Erosion to take over her mind and spread its virus in a new form of disease known as Bubonic Plague. Her bubonic plague became an infection of the lymphatic system, usually resulting from the bite of an infected flea. The disease could be transmitted by direct contact with infected tissue or exposure to the cough of another human. Herrscher's flea was parasitic on house and field rats, and seeked out other prey when its rodent hosts die. The bacteria remained harmless to the flea, allowing the new host to spread the bacteria and gave a chance of Herrscher of the Erosion to spread all over Europe. The bacteria form aggregated in the gut of infected fleas and this results in the flea regurgitating ingested blood, which is now infected, into the bite site of a rodent or human host. Once established, bacteria rapidly spread to the lymph nodes and multiply.

Medieval doctors had no idea about such microscopic organisms as bacteria, and so they were helpless in terms of treatment, and where they might have had the best chance of helping people, in prevention, they were hampered by the level of sanitation which was appalling compared to modern standards. Another helpful strategy would have been to quarantine areas but, as people fled in panic whenever a case of plague broke out, they unknowingly carried the disease with them and spread it even further afield; the rats did the rest.

In a matter of a few months, Herrscher of the Erosion had already infected half of Europe with the Bubonic plague, starting officially the Black Death and the Second Apocalypse, wiping out 1/3 of the world's population. There were so many deaths and so many bodies that the authorities did not know what to do with them, and carts piled high with corpses became a common sight across Europe. It seemed the only course of action was to stay put, avoid people, and pray. To save Europe from the Houkai, the current Bishop of Shicksal allowed Otto Apocalypse and his doctors start human experiments with the Purple Box to seek out the truth behind the plague and put an end to not only the plague but also all Houkai creatures of the world.

When Kallen Kaslena discovered her best friend, Otto Apocalypse (who was still a good guy back then and became the story's Big Bad thanks to Herrscher of the Erosion), was performing human experiments to save mankind from the Houkai plague, she was arrested for discovering the dark secret of Shicksal. With the help of Otto Apocalypse, she later escaped and fought the paladin Eleanor Shariac who was taken by envy due to Kallen's relationship with Otto Apocalypse. During the fight, Eleanor injected the energy of the Purple Box  onto her body and was controlled by Herrscher of the Erosion for a short period of time, transforming her into a monstrous spider-Houkai creature. Otto Apocalypse then shot the creature and helped Kallen escape with the Purple Box from Europe.

Arrival in Japan (Old Script)
In the old script (old manhua of Guns Girl Z), the Purple Box was not being controlled by the Bishop or Otto Apocalypse but was discovered by a small faction of doctors that studied the box and started the Black Death by accident. To rise above God, the leader of the faction used its power to transform humans, mainly heretics captured by the Shicksal to transform them into Houkai beasts, allowing them to create the supreme race under the control of God.

When the Purple Box was going to be transported to Europe in a boat of Shicksal Kallen Kaslana, a devoted nun of their sect couldn't hold her anger towards her leaders when she watched one of her comrades being transformed into a Houkai beast by a Doctor Plague and stole the Purple Box from the crew but had to fight her way through other nun protecting the Purple Box. She defeated most of the nuns but was wounded by a bullet and fell into the ocean with the Purple Box.

Days after, her body arrived in a Japanese village in Japan where she was rescued by the young Yae Sakura. During her rescue, the priestess Sakura opened the box and accidentally freed the Herrscher of the Erosion.

Arrival in Japan (New Script)
During her escape to Asian on foot, Kallen was severely injured by Shicksal's hunters and was rescued by the innocent Yae Sakura who found her by conscident in a nearby river. Like her old script, Yae Sakura opened the box by curiosity which freed the Herrscher of the Erosion and allowed her to take over Yae Sakura's body to use it as her new vessel. The Herrscher proceeded to self-call herself as Yakujin, the God of Disaster and infected Yae's memories to manipulate her emotions.

Yae Village's Curse
As the years passed, Yae Sakura and Kallen Kaslana formed a intimate relationship, something Herrscher of the Erosion planned to use in the future. At some point, the Herrscher of the Erosion cursed the village with plagues and scarcity of food and water, leading the villagers to adopt cruel methods to save their village; sacrificing children to the Gods to answer their prayers. Inside of her body, Herrscher of the Erosion forced Yae Sakura to kill children and infants in sacrificial rituals that were supposedly to be sacrifices to "please the Gods" when in fact it was only giving more power to Herrscher of the Erosion by causing the precious and loved children.

One night, Herrscher of the Erosion took over Yae's body and kidnapped a young girl from the village. In the forest, she tied up the girl in a tree and killed a bear that was just passing by before turning the animal into a Houkai creature and gave the defenseless girl to the Houkai to be devoured alive to strengthen the creature. One day later, Herrscher of the Erosion dispatched the creature to attack the village, killing dozens of men, women and children to force the villagers to sacrifice even more children for their safety. Before the creature could cause more damage, Yae Sakura put down the beast, passing the image of a heroine to give Yae Sakura more familiar power over the population.

The next night, Yae Sakura begun a sacrificial ritual but their ceremony was interrupted by Kallen Kaslana who considered their ceremony heartless and inhuman. Annoyed by her presence, Herrscher of the Erosion transformed herself into a giant ghost fox and devoured the child before crushing her mother with her paws as "thanks" for their efforts. Kallen then faced the white fox creature in a deadly combat but before she could put an end to the creature a masked figure entered in the combat and chained her body. The masked figure said it was just normal for the villagers to be devoured by the God they worship. Angered, Kallen said the white fox was not a God but a Houkai creature full of Apocalyptic energy. Kallen then shoots the masked figure and breaks their mask, revealing the identity of the mysterious person as Yae Sakura who was being controlled by the fox. The Herrscher of the Erosion then explains how she was freed from the box and blames Yae Sakura for everything she did so far due to her hatred for this village that sacrificed her young sister a long time ago. Herrscher of the Erosion then says she is going to destroy the village and destroy everything she and Yae loves the most to make the two suffer for being born human.

After devouring and killing all the villagers, Herrscher of the Erosion burned down the village as a "favor" to Yae Sakura. Arriving at the village, Kallen sees Herrscher of the Erosion seated on the top of a burning temple and challenged her to a death combat. The 12th Herrscher accepted her challenge but stated she is not going to spare her life anymore. After a long fight, Herrscher of the Erosion overpowered Kallen and forces Yae Sakura (who is currently watching inside of her subconscious) to watch she killing her lover but before Herrscher of the Erosion could cut her in half with her katana Yae Sakura breaks out of her mind control and use the katana she was holding to commit suicide to prevent Herrscher of the Erosion from killing Kallen using her own body.

Enraged, the Herrscher of the Erosion returns to her Fox Houkai form and angrily hold her with her mouth while threatening to kill Sakura right in front of Kallen to show how much she is powerless before a "God". Sakura is then devoured by the Houkai beast while Kallen fought the creature in one last fight. Due to her immortality, Kallen Kaslana was forced to seal the creature inside of her own Judah stigmata where Herrscher of the Erosion and Yae Sakura would be kept sealed for the next 500 years. Inside of the stigmata world, the Herrscher of the Erosion altered its space and time and kept repeating the same day that Yae's young sister was sacrificed for 5 centuries to make her suffer even more for betraying her.

500 Years Later
In the modern era (2016 D.C.), when Theresa's Stigmata (Kallen's former stigmata) causes her to lose her consciousness, Bronya concluded something happened with her stigmata which was originally from Kallen (the deceased lover of both Otto Apocalypse and Yae Sakura 500 years ago). To investigate what happened, Raiden Mei is sent to Theresa's stigmata world where she meets a fallen Past Kallen in the middle of a burning village that turned out to be Yae's village after Herrscher of the Erosion destroyed it.

Theresa then awakes inside of the stigmata world and meets Yae Sakura from that world. Knowing she finally had a chance to return to the real world, the Herrscher of the Herrscher of the Erosion took the form of Yae's father and dispatched a horde of Honkai monsters to attack the village and devour the civilians alive to blame Theresa for luring the Honkai creatures to their peaceful village. In a reunion, the Herrscher Erosion (disguised as Sakura's father) proposes sacrificing more children to protect their villages from the Gods' wrath but when Theresa invaded the room to rise her opinion about killing children, the Herrscher of the Erosion threw a rock at Sakura as a way to punish her from bringing such young girl to the village.

Leaving of the room, the Herrscher of the Erosion discovered Theresa was Sakura's last hope and vowed to destroy her so she can be free again. She later had a chat with Sakura to taunt her about all the victims she killed 500 years ago, including remembering her of when she killed hundreds of children in the name of a God that don't even exist when was in fact none other than the vicious Herrscher of the Erosion herself. At night, the 12th Herrscher sent her masked women to capture a sleeping Theresa Apocalypse to sacrifice her. When she resisted, the Herrscher of the Erosion ordered to cut her both of her feet so she couldn't escape.

Child Sacrifice
At the sacrifice ritual, the Herrscher of the Erosion revealed her  plans to sacrifice Theresa so she can take over Theresa's body in the real world and escape from the stigmata world. When Yae Sakura refused to kill her, Herrscher of the Erosion invaded her mind and forced her to remember when she killed her own sister in a similar sacrificial ritual, while in her mind, Erosion controlled her body and impaled Theresa with her katana before disposing of her body. As Yae began to dissolve, the Herrscher of the Erosion embraced her and said she love Sakura and now she is going to drag her to an eternal nightmare within her body.

In the real world, Erosion takes control of Theresa's body and happily laughs for finally being revived after 500 years. She proceeded to attack Kiana and Bronya to celebrate her revival but was quickly knocked down by Theresa's will who was resisting her mind-control. With their defeat, the Herrscher of the Erosion returned to the stigmata and faced Mei in combat after spitting Yae Sakura and Theresa Apocalypse from her mouth. During the combat, Erosion caught the sight of Theresa and Sakura and returned to their original goal of destroying their minds and taking over Theresa's body but a revived Kallen Kaslana appeared before them after 500 years dead. Without wasting time, Kallen began to seal the Herrscher again but before the ritual could succeed the Herrscher of the Erosion invaded Kallen's mind and searched for hatred inside of her memories. There, she found the source of her hatred, Otto Apocalypse and used his form to corrupt her as one last resource to avoid being sealed, however, Theresa showed affection and love for Otto, refusing to fall for the Herrscher of the Erosion's temptation. With nothing more to do, the Herrscher of the Erosion accepts her fate of being sealed again for the time being.

First Samsara (Original Timeline)
In the first Samsara, it shows the old events where Yae Sakura found Kallen Kaslana in a river 500 years ago. After the awakening of Hellmaru and the destruction of the Yae Village, Kallen faced the Herrscher (while possessing Yae Sakura) and was eventually forced to seal her away when the vicious Herrscher tried to control her body.

While being restrained by Kallen, the Herrscher yelled at Sakura for "betraying" her after she gave her power and revenge. The Herrscher of the Erosion vows to destroy Sakura but is sealed away by Kallen inside of her stigmata as the only option to stop her evil.

Second Samsara (The Herrscher Wins)
In the second Samsara of the Virtual World, the Herrscher of the Erosion takes over the body of Yae Sakura and proceeds to kill every single villager of the Yae's village while Sakura was conscious. During the final battle, Kallen fought the Herrscher in a deadly battle after discovering the Houkai sealed inside of the Purple Box was freed.

Despite her efforts, Kallen is eventually killed by the Herrscher after being impaled by her katana and had Sakura to watch it to break her spirit and have her soul for herself. The Herrscher of the Erosion then laughs madly and claims Sakura's soul will belong to her forever as she rise to power once again and destroy mankind in a global epidemic.

Third Samsara (Happy Ending)
In the third Samsara, after destroying the village, Yae Sakura managed to regain her consciousness and broke off the Herrscher of the Erosion's control (with the power of love) after she was about to kill Kallen right in front of her. Freeing herself from Hellamaru's control, Sakura worked together with Kallen to defeat the Herrscher and purify the Houkai energy that had been shrouding the village for a long time.

After a long and deadly battle, the Herrscher of the Erosion is eventually defeated and had her energy purified by Kallen Kaslana's stigmata that was keep her alive for thousand years. With nothing more to use as weapon and attack, the Herrscher of the Erosion falls to her knees in defeat and curses Sakura and Kallen for being two stubborn brats before she becomes dust and is wiped out of existence.

With the Herrscher of the Erosion finally dead, the Black Death on Europe ceased and the plague was extinguished, putting an end to her last trace of existence. Following the destruction of the Yae village, Kallen Kaslana and Yae Sakura married and were finally able to live a happy and peaceful life from then on knowing the world was safe.

Soul Throne Raid
In another Samsara, Sakura and Kallen were lying down on the meadow (before their fight with the Herrscher of the Erosion) but Kallen suddenly told Sakura that she had to leave and vanished in the light. Sakura then returned to the village to investigate her whereaboits. When she arrived in the village, she noticed the villagers had been acting strangely, prompting her to investigate what was causing them to behave strangely. After walking around the village Sakura found a barrel and inside there was a strange human creature called Higyokumaru that was a small girl with a fox-like appearance and was revealed to be Higokumaru, the former vessel of the 12th Herrscher and a part of the Herrscher but couldn't remember her past. Sakura brought Higokumaru along on her search for Kallen while trying to find answers about Higokumaru but had to fight several villagers who tried to stop her from leaving with Higokumaru. Higokumaru then asked Sakura to bring her to the Celestial Pavilion to help find her lost memories as she felt another part of her was in there. On their way there, they encountered numerous Houkai monsters that were triggering Higokumaru's memories.

Upon reaching the temple, Higokumaru, under Sakura's protection, touched a strange sword that was full of Houkai energy, causing her be possessed by the Herrscher of the Erosion (her true-self) once again and transformed herself into Jizo Mitama, a legless samurai whom Sakura defeated after asking Jizo Mitama to quit her revenge but the latter refused once she remembered Sakura was so happy when she defeated her back then.

After fighting and defeating the Houkai, Higokumaru was free from her control and fully recovered her memories of the past, even the memories when she was the 12th Herrscher in the Old World and when she was killed by Fire Moth scientists even after she begged to not be killed, and apologized for all the suffering and pain she had caused to Sakura and Kallen, which Sakura happily accepted as they changed their focus to find Kallen. Higokumaru then told Sakura that the Kallen they were searching for was merely an illusion from her memories, a hologram. Even so, Sakura sais she still wanted to find the missing Kallen in the stigmata dimension.

Without warning, the missing Kallen Kaslana appeared in her phantom thief getup and stole Jizo Mitama away stating this power is too dangerous to be left in such open place. Sakura recognized Kallen's voice and went to chase after her along with Higokumaru. When the two found Kallen again, the latter apologized and chained Sakura in order to stop her. Kallen, who had lost her memories, said that she had to take the sword away because it was dangerous for being a Houkai creature. Sakura reached her hand out to touch Kallen's face and told her that she was here for her, and not the sword. However, this made Kallen's memories come back, but the sword went berserk again because Kallen's will was weakened thanks to her love for Sakura.

Jizo Mitama awakened again and tried to have her revenge on the trio. After the three defeated Jizo Mitama for the second time, Higokumaru offered to use the sword to resurrect Sakura's consciousness into the real world so she can return to the real world physically. Sakura, however, declined her offer, saying that staying here in the stigmata dimension is enough for her as long she have Kallen. The sword was later thrown into the real world right in front of Shicksal's HQ. The Herrscher of the Erosion is currently sealed inside of Judah's Stigmata World where she will be locked forever.