At some point, Valkenhayn's life was saved by Clavis. The wolf swore his loyalty to the vampire from then on, and served his other daughter, Rachel Alucard as the family's loyal butler. He also became acquainted with Tomonori and Jubei as they worked under Clavis when the Dark War began and destroyed Japan. At some point, he also met Yuuki Terumi. When the Dark War finally began, it was Valkenhayn who delivered the news to Clavis about the United Nations' decision to launch nuclear strikes at Japan in order to kill the Black Beast.[6]
Just as the year 2100AD began, Rachel brought back an injured man to the Alucard Castle. Valkenhayn tended to the man's wounds, managing to bring him back from the brink of death and healing the flesh wounds on his body. When the man awoke, Clavis, Valkenhayn, and Rachel were present, and the butler allowed his master to tell the man about his situation. When the time was appropriate, the butler took his master out of the room, giving the injured man time to rest.[7] A week later, Valkenhayn carried the injured man into the basement of the castle, staying a few steps behind both Rachel and Clavis. The man regained some memories of a girl called Tsubaki Yayoi and his brother, called Ragna the Bloodedge. The man had an outburst of emotion when Clavis told him that those people were destined to meet their same fate, and Valkenhayn attempted to keep the man from furthering injuring himself. At the end of a long corridor within the basement, the group stopped and entered a small room which contained the Sankishin - Susano'o Unit. This injured man, Jin Kisaragi, was gifted the Unit, and became Hakumen.[8]
In the January of 2106, Rachel teleported Tomonori back to the Castle and the beastkin spoke in a derogatory tone towards the elderly vampire. Valkenhayn warned him to remember who he was speaking to and nearly bared his fangs, yet Clavis ordered him to demonstrate patience. He poured his master some tea, withholding his reply to Clavis' observation on how he cannot stop humanity from acting.[9]
Daughter, master, servant
Clavis discovered that Tomonori had taken the Hihiirokane to kill Kazuma Kval and Terumi. Valkenhayn was sent after him, but the wolf was too late - Tomonori lay dead in a puddle of blood with Kazuma standing victorious over his corpse, having merged with Terumi. Valkenhayn hunkered low and rushed towards the student before grabbing his skull; knocking him unconscious, Valkenhayn carried him back to the Castle. Together with Clavis, they locked him in a specially made prison, using sorcery to further imprison Kazuma.[10]
Some time shortly afterwards, Rachel delivered Mitsuyoshi, Celica A. Mercury, and Ragna the Bloodedge to the Castle. Valkenhayn took the beastkin into the inner sanctum for treatment before taking Clavis to meet his guests. He reminded Ragna to watch his tone and language in front of Clavis, and soon afterwards was ordered to prepare the rooms the guests to stay in for the night.[11] When Clavis died a short time afterward, Valkenhayn was left heart-broken, but continued his oath to protect Rachel. In his will, Clavis left a note to Valkenhayn, telling him to allow a woman called Nine to release Kazuma from his chains. Together with Rachel, Valkenhayn hosted Nine, Celica, and Trinity Glassfille as they anxiously awaited the return of Mitsuyoshi and Ragna from a battle with the Black Beast. Only Mitsuyoshi had returned.[12]
When the time came, Valkenhayn took Nine and Mitsuyoshi to the Alucard Castle and allowed them access to the prison that housed Terumi and Kazuma. He watched as Nine undid each sorcery lock and as she used Mind Eater; when the group left the prison, Valkenhayn said a quiet prayer to Clavis, asking if what had happened would be alright.[13]
In the months following Clavis' death, Valkenhayn was recruited by Nine into joining a group of warriors who could defeat the Black Beast. His time was divided between serving Rachel and being in various meetings in the Magister's City of Ishana. This group of warriors also included Trinity, Nine, Hakumen, Terumi, and Mistuyoshi (who had changed his name to Jubei); history would remember them as the Six Heroes. In August, 2107AD, Valkenhayn was present for a meeting on the status of the representatives of various nations which had been attacked by the Black Beast. He showed disdain for humanity arguing when they were in such a precarious situation. The meeting ended when they noticed that Hakumen had slipped out, and after a brief search, found the knight with Celica. Valkenhayn left the group after Seven and Eight reprimanded Nine for bringing the group into the Mage's Guild.
Valkenhayn and Hakumen later met with Rachel in the Alucard Castle; the Castle had recognized Rachel as its mistress and its once derelict gardens were abundant with beautiful roses. They discussed what to do with Terumi as Valkenhayn knew the dangers concerning him being allowed to roam. Although he wished to assassinate the man while he was still under Mind Eater, but Rachel dissuaded him, telling her butler that not only is Terumi immortal, but a vital piece to the war's victory effort.[14]
Another meeting was held in the Mage's Guild, this time concerning an ambush on the Black Beast as it came out of its one year slumber. Nine asked Valkenhayn if they could rely on Rachel's assistance with her teleportation sorcery, but the butler did not answer as his mistress appeared to do so herself. Hakumen and Nine's comments towards his mistress greatly angered Valkenhayn, as only he understood that Rachel could not give them her assistance no matter how much she wished to. The meeting ended when Rachel gave them a hint - the Beast would appear wherever Celica would be.
The Six Heroes and battalions of Ars Magus units, the first of their kind, waited in a desert in Eastern Europe for the Black Beast. Valkenhayn was given command of the largest unit, and when he saw the Beast appear, he said a small prayer to Clavis in the hope that he might find the strength to move his body forward. Transforming into his wolf form, Valkenhayn helped launch an assault but stopped when he saw Seven and Eight summon Gigant: Take-Mikazuchi to the battlefield. The monster launched an attack so powerful that the Beast was forced to retreat, giving humanity the first ever victory against the Beast. The lycanthrope ran at full speed to Nine's side, finding Celica unconscious beside her. He asked the witch what the monster was, learning that it was something that she had created.[15]
A few days after the first victory against the Black Beast, Valkenhayn stood at the site where the battle had ensued. Beside him stood Trinity, Hakumen, and Jubei. The lycanthrope could not comprehend the sheer devastation that was laid out in front of him; he spoke, every word filled with anger about how Take-Mikazuchi's destruction was no better than the Black Beasts – he even began to question the worth of the resistance against the Beast if this was the price to be paid. Turning his attention back to the efforts at hand, Valkenhayn suggested that they return to Ishana so that they could focus on the next course of action. Before they could take their leave, however, the four heroes were quickly surrounded by the OLN.
The group was escorted back to Ishana, where they met with Terumi in the Cathedral. Trinity left and returned with Nine in tow. The Sage revealed that Take-Mikazuchi was actually revived technology from an era known as the Age of Origin and it was used in a war. She inferred that Clavis was a part of this war, but Valkenhayn was unaware and made that clear to her. Nine continued, telling them that the Hihiirokane and a weapon known as the Sealed Weapon Izayoi were also from this era. The knowledge that Take-Mikazuchi was revived unsettled Valkenhayn, but he accepted it. Before Nine could tell them more, the OLN entered the building, lead by Seven and Eight. They arrested Nine and took her to the Committee of Hearing for a trial, leaving the other heroes behind and in the dark about what was about to happen.[16]
This mystery was cut short as more OLN soldiers flooded the cathedral, this time raising firearms at the group and announcing that they were under arrest. Hakumen annihilated the entire battalion in under a minute and dashed forward towards the Ishana hospital where Celica was staying; Valkenhayn attempted to stop him but was unable to, and told the group that he did not have the power to take them all to the Alucard Castle for safety. Trinity suggested instead that they all return to her workshop, which they could use to lay low. Valkenhayn turned into his wolf form and carried her through Ishana with Jubei and Terumi behind them. The group managed to avoid the Mage's Guild and prying eyes, and eventually reached an intersection where they reunited with Hakumen, Celica, and Nirvana. Together, they entered the small, yet hidden, workshop. Valkenhayn expressed his disbelief that Terumi had willingly come with them, but before the group could decide what to do next, the sounds of a large explosion rung throughout the city.
As the group ran towards the source of the explosion, they found Nine locked in battle against Seven and Eight. OLN soldiers and the Ten Sages were also on their way . Unable to allow Nine to continue this fight, Valkenhayn quickly turned into his wolf form and grabbed Nine by her collar before swiftly turning back into a human – he carried her to the rest of the group as they decided to retreat from the pursuing soldiers and Sages. Two shadowy figures appeared before the group, but Jubei made the group aware that they were friendly. The figures guided them to a secluded forest where Nine was able to gather up her energy before teleporting them all away from Ishana and into a different location[17]
Now miles away from Ishana, Valkenhayn watched as Nine beat Terumi to the ground for one of his casually rude remarks, shaking his head in disapproval of Terumi's behaviour. He listened as the two shadowy figures introduced themselves as Suzukaka and Totokaka of the Kaka, a race created from Jubei's genes. Valkenhayn's chimed in on the conversation, reminiscing on how every country in the beginning of the war was in chaos. Eventually the group was guided by the Kaka to their hidden village. In the evening, Valkenhayn made tea for the heroes as Nine continued her explanation on Logic, the Age of Origin, the Black Beast, and Take-Mikazuchi.[18]
The following day, Valkenhayn and the other heroes followed Hakumen and Trinity to an old train station. After following its tracks, they came to a tunnel and entered it. Deep within the tunnel was a cavern filled with glowing blue crystals. Celica began to glow, leading Hakumen to realize that they were imbued with the Power of Order and could neutralize seithr. A Kaka ran into the cavern, telling them that there was urgent news back in the village.
In the Kaka village, the heroes came to learn that the OLN and Ten Sages were gathering tens of thousands of people within a village in Asia. Nine deduced that they were going to sacrifice these people to summon Take-Mikazuchi. Unable to allow this to happen, the heroes began to devise a plan to stop them. [19] Nine then teleported the heroes, including Celica, Suzu, and a group of Kaka, to the outskirts of the Asian village.
There, Valkenhayn was reunited with Rachel. She took a backseat to watch the events unfold as Valkenhayn was ordered to help lead the evacuation with Trinity. He obeyed and watched as both the Black Beast and Take-Mikazuchi appeared once more to do battle. Valkenhayn was caught in the seithr explosion caused by the two of them struggling against one another as they sunk into the magic circle used to summon the Nox. Valkenhayn then awoke, alongside the heroes, Suzu, and Eight, in Ishana, having been mysteriously teleported there. Over a hilltop, he saw the Beast chewing on Take-Mikazuchi's shoulder. It stopped and looked up at the group. The Beast smiled at them, and disappeared. [20]
After Take-Mikazuchi had crashed into Ishana, the heroes were no longer considered a priority by the Guild and were instead asked to help with recovery efforts, something which they agreed to do. Despite their offer to help, the OLN remained cautious and had guards constantly following the heroes. The following morning, Valkenhayn found Celica working hard to help the citizens who had been caught in the impact. Seeing the exhaustion on her face, he asked her to return home and rest, otherwise he would force her to do so. She ignored him and went to heal a woman a short distance away.
Celica collapsed and Valkenhayn caught her before gently placing her onto a nearby step. He continued to chide her until Jubei found them and asked him not to preach; regardless, they shared the same concern for her and were aware of the stubbornness of the Mercury sisters. Soon afterwards, Nine had arrived. She told them of her suspicions about the Mage's Guild and Duodecim likely looking to merge with the OLN. Seven interrupted her, and in tow was Eight, Three, and Four. Three told them that she was aware of who he is, but when Nine and Eight began to shout endlessly at one another, he decided to take his leave and make Rachel aware of what had been decided in Nine's meeting.[21]
Two days after Take-Mikazuchi had crashed into Ishana, Nine summoned the heroes together and made them aware of a plan she had devised: to use half of Take-Mikazuchi's core to create new weapons, the Nox Nyctores, and use them to finally kill the Beast. However, she needed time that they did not have, so they devised a plan to stall the Beast and grant the Sage the time needed to finally rid the planet of its seithr-ridden nightmare. The armies assembled to deal with the Beast were from around the world, and Valkenhayn was the most important contributor to keeping them all organized. His experience which spanned lifetimes was instrumental in keeping the army camps together. Valkenhayn and the other heroes, bar Nine, were all present at the camp set up near the place where they would stall the Black Beast.
One month after the camp was created, the Black Beast finally made its appearance known, signalling its approach with towers of black seithr rising in the air. Valkenhayn, Hakumen, and Jubei stepped forward to meet it, with Valkenhayn turning into a wolf and rushing forward as the army followed behind. In response, seithr from the Beast surged forward and transformed into an army of monstrous creatures. Creatures went to grab the wolf, but he kicked as he ran past, snapping their necks. The heroes realized that the seithr was going to encircle them instead of fight them. Valkenhayn ran back, ordering the soldiers to retreat but it was too late as the circle was completed and the Black Beast burst through the center to devour them one-by-one. While the soldiers panicked and attempted to flee, the heroes stood their ground to fight the Beast. Hakumen demanded that Valkenhayn and Jubei fall back, but they were adamant they would stay and fight. Their bickering was cut short by Ayame Yayoi, who appeared before them and cut down the monsters with the Sealed Weapon Izayoi. She cut a path through the seithr that surrounded the army, buying them an escape route that also enabled the heroes to retreat.
The Black Beast did not pursue them, seemingly losing interest. Valkenhayn and Jubei met with Hakumen, who told them that Ayame had lost her life to the Izayoi after using it to save them. But they had no time to mourn as a soldier ran towards them, making them aware that the seithr in the camp was swelling as the Black Beast was attempting to ambush them in the night. Valkenhayn ordered the troops to retreat as he ran forward into a forest, telling Hakumen and Jubei that he would signal if it was safe. There, he found the Black Beast waiting for him. [22] Valkenhayn escaped, but they had to hold out for one month and this was just the first day.
Somehow, they managed to stall the Beast for a month, but at a cost: half of the army had died during the month. They returned to Ishana by boat, where they learned that the Nox Nyctores had been completed. Nine approached Valkenhayn in private, asking if he wanted one but he refused, telling her that he had no need for one since he existed outside of Logic and could fight the Beast with his body. Still, Valkenhayn was summoned with the other heroes and Celica where Nine gave them their Nox Nyctores. Valkenhayn explained his position to the group and watched as they received their weapons: to Trinity went the Arma Reboare: Muchourin, to Jubei the Mucro Somnio: Musashi, to Hakumen the Interfectum Malus: Ookami, to Terumi the Geminus Anguium: Ouroboros, and to Celica was returned the Deus Machina: Nirvana. Nine then explained that the weapons were to be sealed after the Dark War as they had too much power for humanity to handle, and that there was severe mental side effects for wielding them.
Ishana rallied together with the remainder of humanity to strike the Black Beast for one final time. Hakumen summoned the other heroes and Celica to Trinity's workshop. There he revealed that they were not going to be able to kill the Beast. Their mission was simply impossible unless they tried something else. To this end, Hakumen proposed that Celica go inside the Beast and meet with Ragna. Together, they could fight against the heart of the Beast, Nu-13, causing the Beast to lose some of its intelligence and succumb to its base desires of wanton massacre. It would be baited to follow after a large army, bringing it closer to the Kaka Village and the cave near it which was filled with crystals of Order. These crystals neutralize seithr, so the Beast will only get so close. Once it was close enough, the Ten Sages and strongest members of the Mage's Guild would work together to teleport the Beast above it. The Black Beast would be drastically weakened and could then be killed. In order to do so, however, both the body and the heart would have to be killed at the same time as they shared a life-link. Jubei offered up a solution to get Celica inside the Beast: using the Hihiirokane to cut through it, and then using Nirvana to retrieve her. The plan was eventually agreed upon.
Hihiirokane was kept in Castle Alucard, so Valkenhayn took both Jubei and Hakumen to meet Rachel and seek her permission to take it. She agreed to gift Hihiirokane to Jubei so long as he agreed to accept the role of Terumi's slayer. Jubei accepted and Valkenhayn handed him the sword. Rachel also offered him the chance to take the Eye of Tomonori, an artificial eye based on Tomonori's eyes which had seen Terumi's spirit form. Jubei accepted this offer so both Valkenhayn and Rachel took him to another room where they proceeded to implant the prosthetic eye.[23]
Ten days before the Beast was due to appear near Ishana, Nine held a meeting where all the organizations of the island were present. Valkenhayn was in attendance and Nine explained Hakumen's plan to them, albeit with details tweaked. She did not reveal the involvement of Hihiirokane, Celica, or the Beast's heart as it was not something they would understand, and without understanding it, they were unlikely to throw support behind the plan. Valkenhayn was put in charge of the teleportation of the Beast, being the one to make the order of when to teleport it above the cave of Order crystals.
On December 31st, 2109, the Black Beast finally appeared. As soon as it rose from the ground, Hakumen and Jubei were able to complete the task of getting Celica inside the Black Beast. Soon after, the Beast lost all sense of reason and began attacking mindlessly before being drawn forward to the teleportation circle set up by the Ten Sages. One of the heads lunged forward at Nine. Her attention was drawn completely to the circle, but before it could kill her, Valkenhayn ran forward and caught its gaping maw with both hands. He screamed out to the Sages, telling them it was in the perfect position to teleport. Valkenhayn, still holding the gaping jaw of the Beast, slammed it down hard into the ground, allowing Jubei and Hakumen to cut down on its neck with Musashi and Ookami, decapitating one of its many heads. The Beast and the heroes were then teleported to the area above the cave that neutralizes seithr.
Together, the heroes worked in unison. The Beast was writhing in pain and could no longer regenerate its wounds. Both Jubei and Valkenhayn attacked the Beast straight on, landing as many blows as possible, something that inspired hope in the nearby troops. Hakumen ordered that they decapitate each head one-by-one. Valkenhayn turned into a wolf and ran up the Beast before turning human again. Trinity amplified his power with magic and Valkenhayn punched clean through the Beast's neck, decapitating one of its many heads. Slowly but surely, the heroes managed to decapitate every head until the Beast suddenly stopped moving.
Rachel appeared nearby with Celica and Nirvana in tow. The heart of the Beast was dead. The body began to deflate, coming down to the size of a man who was a similar shape to Ragna. Hakumen walked forward and decapitated with one swing of Ookami. The Black Beast was dead, and the Dark War had finally ended.[24] Valkenhayn, Hakumen, Nine, Jubei, Trinity, and Terumi were granted the title Six Heroes because of their incredible bravery and influence in ending the war. Both Valkenhayn and Nine hated the title.[25]
Rachel went to sleep, slumbering for over 50 years once the war had ended. Valkenhayn left for her side and never left. It was only some years later that he discovered that Terumi murdered Nine and Trinity, and that Hakumen dragged Terumi into the Boundary. At some unknown time later, he reconnected with Jubei, they being the last two of the Six Heroes still alive.[26]