The Yonkishi (四騎士)

They Who Ride Forth on Calamity

The Yonkishi

Nearly 500 years ago, when humans were still new to the land, their relations with the Yokai were not as friendly as they are today. Most of them were willing to coexist and guide the humans towards prosperity…but there were also many who believed humans were inferior and deserved to be subjugated. That faction was led by four extremely ancient, unbelievably powerful Yokai called the Yonkishi; They who Ride Forth on Calamity. The Yonkishi despised the notion that Yokai were to live amongst humans as equals. They believed that it was the humans who should serve them. The Saint of Tranquility, Saiha el-Ryugamine pleaded with them to see reason, but they were adamant. They continued to kill humans, to “purge the land of the impurities”. Saiha knew he could not tolerate their actions any longer.
The de facto leader of the Yonkishi, Mugen embodies the primal fear all living creatures have of death. Wherever he walks, animals and plants die around him. With but a glance, he can end lives. He wields an ethereal black scythe wreathed in miasma. Because of his abilities, he was deemed as the most dangerous of the Yonkishi during the war. Mugen views death as nothing more than a part of the natural cycle of life. He is not inherently evil, but will do whatever he must to accomplish his goals. Though he views humans and other humanoids as inferior, his goal is not to wipe them out completely. He simply wants their subservience.
As cunning as she is beautiful, Sayuri is sly and intelligent, making her all the more dangerous a foe. A master of manipulation, Sayuri excels at destroying enemies from within (literally and figuratively). The pestilence she spreads across the land is vile, causing painful deformations and hideous bodily transformations. Her weapon is a katana that extends the range of her plague. Sayuri is the mastermind of the Yonkishi, her cunning mind is at the center of their goal to dominate the humanoids. She will use any one around her, even her fellow Yonkishi to further her goals. She is aware of Agito's feelings for her and uses them to her advantage (though she may reciprocate more than she lets on). Sayuri holds the most contempt for humans among the Yonkishi. In fact, she was the one who reached out to the other Yonkishi and instigated the First Great Yokai War. She views the humanoids who've spread across Koryo as a blight that are corrupting the land and undermining her very existence. Like the Jigoku Tayu and Yaya, Sayuri once admired humans. However, after seeing their greed and destructive tendencies, she grew to hate them.
Quiet and reserved, Agito rarely makes his own decisions, only moving as Mugen and the other Yonkishi command. On the battlefield, however, he is peerless in skill. Of the Yonkishi, he is easily the best combatant, often fighting alone on the front lines during the First Great Yokai War. He wields a set of scales that he uses to judge the souls of the unworthy. He also harbors a one-sided love towards Sayuri. Unlike his romantic interest, Agito only finds humanoids to be mildly off-putting. If not for his loyalty to Sayuri, he would have no part of their plan. Agito is the most good-natured of the Yonkishi and dislikes suffering and unneeded death. Unlike the other Yonkishi, Agito loathes his power. He despises the fact that it drags out his victims suffering resulting in slow, agonizing deaths. He would rid himself of it if he could.
The youngest of the Yonkishi, Setsuna is brash and hot-headed, quick to let her emotions get the better of her. She is often scolded by the other three because she has a bad habit of letting her temper control her. She wields a powerful bow that can harness the power of maelstroms. Setsuna revels in destruction. She believes that since all life stems from water it should be water that brings about it's end as well, destroying everything with the power of the torrential flood. Wherever she walks, water springs forth from the nearest source. Of the Yonkishi, she boasts the highest destructive capability. Setsuna dislikes humanoids, but has nothing personal against them. She joined the Yonkishi mainly because their goal allows her to freely use her powers.

The First Great Yokai War

Along with his Ayakashi and other allies, Saiha fought against the Yonkishi in a brutal civil war over the balance of power between Yokai and human. After nearly 5 years of bloody battle, Saiha realized that killing the Yonkishi would be nigh impossible. Instead, using what remained of their powers, Saiha and his remaining allies sealed them into the land itself. But they knew that would not be enough to contain them for long. And so, Saiha's surviving Ayakashi made the ultimate sacrifice. They bound themselves to the land and used their essence to strengthen the bindings on the Yonkishi. As a happy side effect, their essence filled the land and helped it prosper. That is the true identity of the Tochigami. Each of the dozens of Tochigami shrines scattered about Koryo are locks meant to keep the Yonkishi restrained.

The Yonkishi Freed

Years passed, then decades passed, then centuries passed. The Yonkishi were soon forgotten, written off as nothing more than myth. But their Disciples did not forget. The Yonkishi's followers were not limited to Yokai. Fanatical humans pledged their allegiance as foot soldiers and servants. The Yonkishi shared their powers with a select few of them to create the Disciples of the Yonkishi. After their defeat, the surviving Disciples fled and waited until the time came when they could free their masters. They passed down stories and knowledge to their descendants, raising them as cult fanatics who would follow in their footsteps. After 500 years of waiting, they finally devised a method to destroy the locks binding the Yonkishi: By using miasma to simultaneously destroy the shrine and the Tochigami within.
With enough of the Tochigami shrines destroyed, the seal was loosened to the point that one by one, Setsuna, Sayuri, and Agito were able to free themselves from their binds. Mugen, however, was sealed in Tengoku under the protection of Asuramaru, Saiha's most powerful Ayakashi. Weakened by the side effects of having been sealed, the other three Yonkishi knew that they would have no chance of freeing Mugen while both Saiha and Asuramaru remained in Tengoku to guard his shrine. But luck favored them in the end. The fall of Babylon and Saiha's resultant death provided them with the perfect opportunity to strike. Without Saiha there to stop them, the other three swept into Tengoku with their Disciples and obliterated it, wiping out any and all who were unfortunate enough to cross paths with them until they finally reached Asuramaru's shrine. Together, the three of them overwhelmed the Ayakashi and succeeded in freeing Mugen from his seal.

The Second Great Yokai War

Tengoku now nothing more than smoldering ruins, the Yonkishi begin to finish what they started half a millennia ago. Sending their Disciples and conquered Yokai forces across the land, they will not stop until every humanoid in Koryo has bent the knee to them. The only resistance against them are the Onmyouji in Abe no Seimei, the rangers of the Twilight Enclave, a handful of Yokai in the Grindstones, and a few other brave warriors. So begins the Second Great Yokai War.

The Song of the Yonkishi

I watched as They opened the first of the eight seals. Then I heard one of the Four living creatures say in a voice like thunder, “Come Forth!” I looked, and there before me came a deluge of water of quantity enough to drown the land, surging forth from the feet of its Creator! Its Creator was named Setsuna, and They were shackled yet given the power to cleanse the land of impurities. Then I heard what sounded like a voice among the Four living creatures, saying, “When the flood came the rain fell all the harder, water on water gushing over the land. In the darkness the gurgles of the drowning sounded all the louder to the sightless eyes.” And They rode out as a torrential flood, bent on conquest.
When They opened the second seal, I heard the second living creature say, “Come Forth!” Then from within came a swarm of vermin and a cloud of locusts of quantity enough to poison the land, swarming forth from the mouth of their Creator! Its Creator was named Sayuri, and They were shackled yet given the power to take peace from the earth and to make people kill each other. Then I heard what sounded like a voice among the Four living creatures, saying, “I am Pestilence, come to claim your world. I am eternal and my task unwavering.” To Them was given a large sword, and They rode out as a suffocating plague, bent on conquest.
When They opened the third seal, I heard the third living creature say, “Come Forth!” I looked, and there before me was a barren landscape, riddled with the bleached bones of all those who had succumbed, picked clean by the scourge of rats born at the feet of its Creator! Its Creator was named Agito, and They were shackled yet holding a pair of scales in Their hand. Then I heard what sounded like a voice among the Four living creatures, saying, “And then will come hunger, riding on a cloud of death. They will ride into the land of plenty. And great will be Their hunger, for They are hunger. Their hunger will seep out and poison the air.” And They rode out as a rattling famine, bent on conquest.
I watched as the other Three opened the fourth seal. I heard the voice of the Fourth living creature say, “Be Reborn!” I looked, and there before me was Death, sprang forth from the feet of its Creator! Its Creator was named Mugen, and Hades was following close behind Him. Then I heard all Four living creatures, saying, “And through the fire was Hades and He who was beside him carried a scythe. And I saw since He had risen, they too shall rise. And from Him, and through Him.” They were given power over the earth to take life, and He rode out as the harbinger of death, reaping the life from everything anything and everything.
When They opened the fifth seal, I saw in the shrine the souls of those who had been slain because of Them and the testimony they maintained. They called out in a loud voice, “How long, Tainted Ones, unholy and untrue, until you judge the inhabitants of the world and return creation to the dust of genesis?” Then each of the souls was given a white robe, and they were told to wait a little longer, until the full number of their fellow servants, their brothers and sisters, were killed just as they had been.
I watched as They opened the sixth seal. There was a great earthquake. The sun turned black like sackcloth made of goat hair, the whole moon turned blood red, the skies split and shattered and the stars in the sky fell to earth, as figs drop from a fig tree when shaken by a strong wind. The heavens receded like a scroll being rolled up, and every mountain and island was removed from its place.
And I stood and watched as They turned to the seventh and eighth seals, cooing over them and caressing them as a mother to her newborn babe.
Then the kings of the world, the princes, the generals, the rich, the mighty, and everyone else, both slave and free, hid in caves and among the rocks of the mountains. They called to the mountains and the rocks, “Fall on us and hide us from the face of Them who sit on the throne and from the wrath of the world! For the great day of Their wrath has come, and who can withstand it?