Klaus Von Reinherz (クラウス・V（フォン）・ラインヘルツ, Kurausu Fon Rainherutsu) is the leader of Libra and young head of the noble Reinherz family.
Klaus is a large, red-haired man with a distinctive under-bite, green eyes, and side-burns. He wears a white shirt with a red tie under a black waistcoat, as well as black pants with brown dress shoes. He also wears glasses.
Known for his gentlemanly composure, honest to a fault nature and unshakable will, he typically conducts himself in a calm, polite manner unless suitably angered, in which case he will lash out with a beast-like level of savagery.
Due to his nature, he tends to over-stress himself worrying for the safety of others (particularly Leo) and will often put himself on the line to save them, something Zapp and Daniel Law, a HLPD lieutenant, have taken advantage of.
An avid botanist and Prosfair player, his office contains several potted plants which, if damaged or otherwise upset, is a sure-fire way to anger him according to Zapp.
It is implied during Gilbert's injury that Klaus will not accept tea brewed by anyone else, though he is later shown to be quite adept at brewing it himself.
Kekkai Sensou: Bloodline War
At some point prior to the story, Klaus, a victim of a vampire attack, was sealed away in a giant stone crucifix, his infection having progressed to level 12 (at 13, he would become a Blood Breed).
He is approached by a figure resembling 'Lucky' Abrams, who offers him the chance to turn his life around, though he may die in the attempt.
Years later, Klaus confronts Count Urthrchika on the side of a skyscraper, managing to separate him from his hostage, Reina, only for the Count to escape by severing his own finger.
After receiving a report from Chain Sumeragi and unintentionally frightening Reina alongside Gilbert, they learn of how she and her friend, Aiko, fell victim to the Count and Klaus comforts her, assuring her that he will defeat the Count before they can become Blood Breeds.
Whilst dining with Reina, the Count's finger begins to move around, prompting Klaus to order Chain to track the Blood Breed. However, the count somehow manifests inside Reina's blood to mock them and threaten Aiko, only to be crushed by Klaus before he can kill Reina.
Learning more about Reina and Aiko's backstory, Klaus vows to save the latter and travels to the Count's hideout with Gilbert, crashing through the wall in their reinforced Rolls Royce. Despite easily outclassing the Count's slaves, the Count himself proves a more difficult foe due to his ability to manipulate blood, taking Reina and Gilbert hostage.
The count mocks Klaus' for his inexperience, citing that blood is not only his lifeblood but also his weapon, only for Klaus to retaliate by using his own Blood as a weapon, injecting it into the Count's body, destroying his cells/curse from within.
Come the dawn, as Jagtkreuz are saying their farewells to Reina and Aiko, Klaus assures Reina that they will meet again the next time she is in danger, before granting her request to see him smile. He does so, but as Chain reveals, Klaus' smile is easily his most terrifying expression, as evidenced by Reina's passing out foaming at the mouth from fear.
Those Shrouded in Fog.
In the official series, Klaus introduces himself to Leo after Zapp brings him to his office, believing him to be their new Member, Johnny Landis. In the manga, he easily fends off an assault from Zapp, comically 'breaking' the man before depositing him in a free spot so as to not disturb his potted plants.
Following Chain's outing Leo as an impostor, Klaus bore witness to Femto's unleashing half a Yog-gphot downtown and ordered her and Zapp to prepare, only to immediately shield Leo with his own body when the second gate (attached to a Flea hidden on the Sonic Speed Monkey) opened in his office.
Realizing that Leo was able to see the monster in the nanosecond before it attacked, Klaus correctly deduced that Leo possessed the 'Eyes of the Gods' and, after hearing his story, invited him to join Libra.
Despite being injured, Klaus' strength of will, and the destruction of his potted plants allowed him to stand up and crush the HLPD forces sent to 'secure' them with a single attack, allowing Leo and Zapp to track down the monkey and destroy the Gate.
In the Manga, he is later seen drinking coffee at the ruins of Vivian's Diner along with an exhausted Chain and Zapp.
Follow That Phantom Ghost Wagon.
In the anime, Klaus is first seen when Leo visits Libra's office, where he easily fends off an assault from Zapp, comically 'breaking' the man before depositing him on the floor.
In the manga, he is first seen in a flashback sometime after Leo's induction to Libra. While Leo initially assumes Klaus' terrifying expression to mean he's angered the man, in truth Klaus was simply worrying himself sick over Leo's well-being to the point that, following his abduction, Steven suspects their leader is nursing 'A Dozen Ulcers'.
After being somewhat put at ease by Steven, they receive word from the Hospital that Zapp's body is absorbing the medical blood transfusions at an unusual rate and realize he must have tagged the Ghost Wagon. Following Chain's directions after Zapp ignites the blood trail, he, Steven and Gilbert pile into the latter's car to give chase.
After a high-speed chase, they finally manage to track the Wagon down and Klaus promptly destroys it to rescue Leo, only for him to be caught up in the attack and hospitalized. Klaus reveals he tried to assign Zapp as Leo's bodyguard but was refused, prompting Steven to tease him for failing to realize Zapp's true intentions.
A Game Between Worlds.
Klaus is seen at his computer in his office, seemingly hard at work while Steven and Gilbert discuss Leo's situation and the spread of the drug Angel Scale. Following the news report of an attack on the US President by an Angel Scale user, Klaus is shown with an intense expression, only to reveal he'd been playing Prosfair the entire time.
While Zapp and the other Libra Agents are sent out to search for Angel Scale's distributors, Klaus and Gilbert rendezvous with K.K, Klaus voicing his concern for her safety upon learning she was ambushed, much to her pleasure. Together, they make their way deeper into the mist in order to gain the information needed to crack the case.
At Don's church, Klaus is startled by the presence of Chess Grandmaster Ulchelko. Upon realizing that Ulchelko intends to challenge the Don to a Prosfair match, he urges him to reconsider but upon being shot down, he advises Ulchelko to 'remove checkmate from his strategies', knowing all-too-well how strong a player the Don is.
When Ulchelko is defeated, Klaus intervenes on his behalf and the Don concedes, provided Klaus 'entertain' him for 99 hours of non-stop Prosfair. During the course of the game, the Don attempts to weaken Klaus' resolve by revealing one of Ulchelko's requests was for Klaus and K.K's deaths, but Klaus's will remains unshaken.
After 99 hours has finally passed, an exhausted Klaus is dropped unceremoniously before K.K, who carries him to the surface whilst relaying the location of the drug dealers to Libra. Sometime afterward, Klaus is shown sitting on the roof, playing Prosfair once more.
During a Libra Party, Klaus is seen as part of a 'Cabal', chatting amiably with Steven and several other Libra members. Whilst inquiring as to Leo's wellbeing, the young man unwittingly reveals that he saw the Aura of a Blood Breed Elder in the Subway, putting everyone on edge and forcing Klaus to call in his teacher, Blitz T. Abrams.
When Abrams arrives, Klaus is the only one to seemingly welcome him without visible signs of discomfort. After revealing to Abrams that Leo is the possessor of the 'Eyes of the Gods', he accompanies Leo and Zapp to the Beyond station, where Leo reveals the Fog below is packed to the brim with Vampires.
Shortly after, Klaus is alerted to the Elder's attack on the subway and dispatches Steven and K.K to intervene, or at least buy time for him to get there. Armed with the Elder's true name thanks to Leo, he easily dispatches the Elder's servant, Valsh Rozzo Valctovoel Girika, before using Braingrid: Pattern 999 to seal her away. He is last seen carrying K.K out of the subway.
Day In, Day Out.
Klaus has a minor role at the end of this tale as one of Leo's visitors during the latter's hospitalization following the mass outbreak of short-term amnesia as a result of his friend Ned's spores.
Pandorum Asylum Phapsbody/The Tremorous Blood Hammer.
Klaus and Abrams are seen at Wonderland prison, attempting to have Doug Hammer & Deldro Brody released in order to help stop a literal monster truck driven by the latter's former lover. When the Warden refuses, Klaus is forced to fight her in order to convince her to release the pair into his custody.
Following the warden's defeat, Klaus and Abrams reunite with Doug and escort him to the surface, where they learn that Leo has been captured by the truck. Devising a plan to stop the truck and save Leo, Claus uses his blood cross shield to make a ramp, allowing Hammer & Brody to destroy the truck with a single blow. He later visits Doug in hospital.
E-Den of Master Fighters.
Klaus is working in his office while Leo, Steven and Chain discuss how long it's been since Zapp last tried to challenge him. Moments later, Zapp calls, having apparently been taken hostage, claiming that he'll be killed if Klaus doesn't show up. Despite the suspicions of Leo and the others', Klaus sets off with the boy to rescue Zapp.
Arriving at an underground fighting ring, Klaus is forced to face off against several fighters as part of a scam concocted by Zapp to clear his debt to the owner, who challenges Klaus himself after he defeats the reigning Champ. During the fight, Klaus unintentionally destroys the owner's head, revealing him to be a corpse controlled by a Blood Breed.
Rather than continue the fight, the Blood Breed applauds Klaus skill before easily tossing him out of the ring and vanishing into thin air. After reuniting with Zapp, an exhausted Klaus, still entirely unaware of any deception on the latter's part, humorously defeats the punk off-screen when he once again tries to get the jump on him.
One Butler's Blitzkrieg.
Klaus role in the story is, once again, very minor, though some of his and Gilbert's backstory is explained in that he is the heir to the Noble Reinherz family and that Gilbert is one of their Combat Butlers who accompanied him to Hellsalem's Lot when he took up the post of Libra's Leader.
When it is revealed that Gilbert's assistant and fellow Combat Butler has been kidnapped and his brain extracted, Klaus, naturally, steps forward to rescue him, only to be countered by Gilbert, who points out that doing so would only shame the man. While both Butlers are hospitalized, Leo notes that Klaus is quite capable of caring for himself.
Power and Abilities
Superhuman Strength and Durability: Klaus is easily the strongest member of Libra, able to go foe-to-foe with creatures of Beyond in a bare-knuckle fist fight and even exchange blows with Blood Breeds with little, if any, signs of injury. He is also the only one capable of standing up to Zapp and Zed's Master Raju, hailed as the 'Blood Battle God'.
In the original One-shot, this is attributed to his 'Curse' as a Blood Breed victim advancing to level 12, but in the main series, no mention of this is made. In the main series, it's attributed to his will to survive and protect others.
Power of Sealing and Destruction: Raju addresses Klaus as 'The one with the powers of Sealing and Destruction' through Zapp's voice, has no doubt referring to his ability to seal away Blood Breed Ancestors in addition to his physical prowess.
Superior Intellect: Klaus possesses a sharp, deductive mind which allows him to last for over 90 hours, non-stop, in a Prosfair match.
Knuckle Duster: Klaus uses a unique and distinctive knuckleduster which is strapped to his left arm and usually hidden away until needed in a fight when it drops down with a flick of his arm.
The device is metal, possibly a mix for strength with the addition of a sterling silver cross on the front plate which is traditional European folklore is a known metal to repel and weaken Vampires and other demonic creatures.
Brain Grid Blood Battle Style (ブレングリード流血闘術 Buren Gurīdo-ryū Kettō Jutsu?): Klaus' combat style, allows him to create large, cross-shaped weaponry from his blood to attack, defend and even seal away enemies. The Techniques of this style are announced in German.
- Pattern 02 - Schrott-Schweisser/Shot Welder: Used in the Original Oneshot, creates cross-like shuriken that impales the target, dissolving any Blood Breed on contact.
- Pattern 11 - Wirbelsturm (11式・旋回連突（ウィルブルスツゥルム） Jūichi Shiki - Wiruburusuturumu?, literally "Twisting Storm"): Similar to Schort Sweiser, it creates larger cross-shurikens and is capable of taking down the armored HLPD officers with ease despite being surrounded, implying it is designed for multiple opponents. This is called Form 11 - Wirbelsturm in the FUNimation dub.
- Pattern 13 - Finger Greed: Used in the Original One-Shot, a series of blows that cause glowing crosses to appear on the target's bodies, burning them from the inside.
- Pattern 32 - Stechende Blitzattacke (32式・電速刺尖撃(ブリッツウインディヒカイトドゥシュテェヒェン) Sanjūni Shiki - Burittsu Windihikaito Dushutehien?, literally "Lightning Speed Lancing Attack"): This technique allows Klaus to create a lance mid-air that impales the target as it's taking form.
- Pattern 39 - Keil Barrikade: Creates several miniature crosses to defend against oncoming attacks whilst pinning the enemy in place.
- Pattern 74 - Kreuzschild Unzerbrechlich (74式・絶対不破血十字盾（クレウズアンザーブレクリック） Nanajūyon Shiki - Kureuzu Anzāburekurikku?, literally "Cross Shield Unbreakable"): This technique can summon a cross-like shield. In season 2, it is classified as Pattern 117 (117式 Hyakujūnana Shiki?).
- Pattern 111 - Kreuzvernichterlanze (111式·殲滅槍（クレウベルニクターランツェ） Hyakujūichi Shiki - Kureuberunikutārantse?, literally "Cross Annihilator Lance"): Self-explanatory. A large blood cross used to crush and/or overpower enemies.
- Pattern 999 - Ewigkeit Gefängnis (999式・封縛獄久遠棺（エヴィグシュカイトゲフェングニス） Kyūhyakukyūjūkyū Shiki - Evigushukaito Gefengunisu?, literally "Eternity Prison"): The technique used to seal away Blood Breed Elders by invoking their true name, sealing them in a small crimson crucifix from which there is no escape.
- Pattern ?? - Debunker Von Kreuz Sarg (十字血棺掩壕（ディバンカーフォンクロイツザーグ) Dibankā Fon Kuroitsu Zāgu?, literally "Cross Blood Coffin: Cover Position"): It creates a coffin of a giant blood cross and prevents omnidirectional attacks which can not be prevented by shields by entering into it.
- In the manga official translation, his last name is spelled "Reinhertz"
- The Blood Blockade Battlefront Official Fan Book B5 reveals Klaus's height to be 201 cm, making him 6'7" and his weight to be 136 kg making him 300 lbs.
- In the manga chapter of "One Butler's Blitzkrieg" it's said that Klaus is the third son of the Reinherz household, implying Klaus has two older brothers.
- In the Blood Blockade Battlefront Official Fan Book B5 while nothing is stated about his brothers, it is revealed Klaus is the youngest in the family and has an elder sister.
- Klaus's age was revealed in the Kekkai Sensen radio broadcast, to be 28 years old.
- The Blood Blockade Battlefront Official Fan Book B5 later confirms this and states his birthdate is December 31st, making his Zodiac sign the Capricorn.
- In the Oneshot, Klaus was a level 12 Blood breed. This might still be the case in the manga, which is shown indirectly when he seals other Blood Breed by using pattern 999, by saying "...I hereby seal you. Despise me, forgive me, resign yourself. I take these barbarous actions to protect the human world." By apologizing and admitting that his actions are "barbarous", it may imply that he recognizes himself as 'the same kind' as the Blood Breed, or at the very least, close to the Blood Breed.
- In the Oneshot, it is also revealed his favorite food is liver, this seems to still be true in the manga, as in the chapter "One Butler's Blitzkrieg" Gilbert mentions in his inventory check-list, 18 gallons of condensed liver.
- In the Blood Blockade Battlefront Official Fan Book B5 it's revealed that Klaus’s blood technique is the most strenuous of them all, and he uses the most blood out of all the other Libra members.
- He draws his blood using what seems to be a cross-shaped knuckleduster with a blade pointing towards his arm.