|Base of operations||Van Kleiss' castle|
|Affiliation(s)|| The Pack|
|Hair color||Black with gray streaks|
|Abilities|| ·Can drain nanites from EVOs|
·Superhuman strength and agility
·Hand-to-hand combat skills
|Weapons||Van Kleiss's gauntlet|
|Allies||Biowulf, Skalamander, I-Bol, Gharun Set|
|Enemies||Rex Salazar, Agent Six, Bobo Haha, Noah Nixon, Rebecca Holiday, Circe, Captain Calan, White Knight, Providence, Breach|
|First appearance||"The Day That Everything Changed"|
|Last appearance||"Endgame, Part 2"|
|Portrayed by:||Troy Baker|
|Images | Quotes|
|“||And I live off nanites. What Providence calls a "cure," I call death.||”|
–Van Kleiss, "Written in Sand"
Van Kleiss is the leader of the Pack and Abysus. He wants to take over the world and start a new era for EVO-kind. To help him accomplish this, he has formed a dangerous group of EVOs called the Pack. He claims to know all about Rex and his past, a fact he often uses to try to persuade Rex to join his cause or to stop Rex from capturing or destroying him.
Van Kleiss was a scientist who participated in the original Nanite Project along with Dr. Gabriel Rylander, Peter Meechum, Rafael, Caesar and Violeta Salazar. Van Kleiss was a greedy man and wanted power to himself and believed that the nanites could help achieve that. When finding out that the Consortium was also behind the same objective, he murdered Rex's parents once they caused the explosion after discovering the same thing.
After the Nanite Event occurred, Van Kleiss was in close proximity to the blast. Later on, he discovered that he was gifted with the ability to control Abysus, infused with the nanites from the blast.
After Skalamander pushed Rex, Bobo, and Noah into a portal to Abysus, Van Kleiss walked towards the group as little flowers sprouted around his feet. He then stated who he and his Pack were and what they were there for. Afterward, Van Kleiss directed them to his castle.
As all of them walked through the deteriorated castle, Van Kleiss told them that the nanites were a gift, which Rex swiftly disagreed with. Van Kleiss replied that they're "not all savages" and that Rex had barely realized his full potential. Rex wondered how he could know about his potential when he didn't know anything about his past, to which Van Kleiss said he would tell him about his history. He first told Biowulf to take Noah and Bobo to the garden. After they left, he led Rex to a throne room and told Rex of the Nanite Event.
After he finished, Rex asked what it had to do with him. Van Kleiss replied that it had everything to do with him, at which point numerous roots burst through the castle floor and seized Rex. Van Kleiss said that his body was unstable and required a constant supply of fresh nanites and that Rex's should be very nourishing. Then the pins on his fingers turned into needles and he stabbed Rex's chest with them.
Van Kleiss stated that he was disappointed in Rex for not putting up a fight. Noah and Bobo returned from the garden to where Rex and Van Kleiss were, and Bobo threw a large rock at Van Kleiss, giving Rex the chance to fight back. He kicked Van Kleiss into a wall and the three fled on Rex's Boogie Pack.
The group dodged gigantic roots and trees trying to take them down as they flew away from the castle. Van Kleiss manifested himself through very large trees and asked where Rex was running to, as Providence would just use him as a weapon and lock him up. This caused Rex's nanites to short out and the three crashed into the forest.
During the final fight in Abysus, Van Kleiss kept Agent Six away and the Pack fought as well. However, Rex's nanites reactivated and he went for the final blow on Van Kleiss with his BFS. It hit and Van Kleiss was cut in half, but it is shown as the group left that he resurrected himself from his land.
Van Kleiss only appears at the end of the episode but it is clear that he had his Pack kidnap Peter Meechum's daughter Sarah Meechum so that Peter would be forced to work for him. Biowulf reports that Meechum has been cured and Van Kleiss has no outward response.
Van Kleiss learns from Biowulf (off screen) that his new recruit Circe, had help from Rex in defeating a sea monster EVO, a task that would provide her initiation with The Pack. Yet, Van Kleiss lets her join anyway intending to use their blossoming relationship to coerce Rex to his side.
Van Kleiss arrive with his Pack in a strange whale blimp EVO. Providence, who caught wind of the EVO in restricted air space, has sent units of solders and Rex and Agent Six to intercept it. When it is revealed to Rex who is in the EVO he immediately attacks. He cannot land any blows on Van Kleiss (though he tries) due to his [Van Kleiss's] diplomatic immunity. Rex is understandably annoyed at this but until Van Kleiss or one of his Pack break that immunity they are untouchable.
Van Kleiss, Biowulf, and Skalamander are next seen at a formal party. He greets Rex and Doctor Holiday politely, brushing off Rex's accusations and tells him that "not everything is about you." After Rex is captured he ends the party, thanking all the guests before leaving himself.
After that he is seen with The Pack (minus Circe) walking into the UN building. Biowulf tells Van Kleiss that Rex has escaped, but Van Kleiss says it doesn't matter. After an interlude he steps up to the pedestal and addresses all present. As he is speaking he uses his powers to rise above everyone, trap all inside, and begin to cover all of the city in roots.
Rex and Van Kleiss fight soon after this, with Rex ultimately figuring out how to defeat Van Kleiss as his native soil is dumped into the East River he becomes significantly less powerful but still summons vines to subdue Rex (by trying to strangle him). But after the soil has diffused too much all the roots and vines wither and break apart, freeing Rex, who then punches Van Kleiss (it was a very good punch too). He stops Rex from killing him by saying that he knows about Rex's parents, which shocks Rex. Van Kleiss then takes the opportunity to flee on a giant fly-like EVO.
Van Kleiss is trying to take control of an Amazon base. He is seen with The Pack (minus Circe and Breach) with him. He knocks out Gabriel Rylander a scientist who knows about Rex's past. He is last seen pushed into an unstable nanite reactor and seemingly (as far as we know) vaporized along with Dr. Gabriel Rylander. It is presumed he is dead because Agent Six said "Van Kleiss has been eliminated." But, Agent Six said this according to what he heard from Rex, which is exactly what he tells White Knight.
Due to what happened to Van Kleiss at the Amazon base, Abysus has become increasingly unstable. Circe, Biowulf, and Skalamander had to lure Rex, Agent Six, and Dr. Holiday to Abysus where the only way to stop the unstable nanites spreading is to power a device that will resurrect Van Kleiss. Rex is forced to do exactly that when everyone else starts to drown in the unstable nanite fluid. When Van Kleiss is revived, he absorbs the unstable nanites into himself and continues, but will only save Rex's loved ones, including Circe, in exchange that Rex promises him his eternal allegiance. Rex eventually does so and when he shakes Van Kleiss' hand, Rex knew that the nanites in him were different now and ends up curing him of the nanites. Van Kleiss had stated that he was "incurable" until what just happened. Before Rex can bring him in to Providence custody, Breach appeared and got Van Kleiss away from Rex at the last minute while the rest of the Pack escapes.
Van Kleiss later returns and somehow got back close to his original active nanites giving himself an upgraded bio-mechanical hand(arm), using a spy on a Providence airship Van Kleiss hijacked the ship and crashed it into the Providence base. Van Kleiss drains Rex's nanites giving himself the ability to turn anyone he touches into a EVO (such EVO's are marked with a yellow hand print on the location where they are touched for transformation), the opposite effect of Rex's nanites to cure them. However, Rex is eventually able to inject himself with a supply of newly active nanites, regained his original powers plus new-and much stronger- ones, and successfully defeated Van Kleiss using a new build, sadly Van Kleiss is able to get away using the explosives planted in the base as a distraction.
Van Kleiss led an attempt to steal an energy core that was to be used to power the Providence HQ. As a distraction he transformed a Shoreman into an EVO and when Rex cured him he turned Noah into an EVO as another distraction. Dr. Holiday later was able to determine that the mutations Van Kleiss created were unstable and unless his victims were cured within a set amount of time, they would become incurable. Before Rex could cure Noah, Van Kleiss scared him away. After a chase through a subway, Rex confronted and defeated Van Kleiss using yet another new build and Noah's help. However, Van Kleiss revealed that he was a third distraction, allowing Breach to steal the energy cell and then rescue him.
Van Kleiss and the Pack ventured into the Bug Jar to forge an alliance with NoFace in order to use him and his EVO army to conquer the world. When Rex was captured by the Pack, Van Kleiss gave him to NoFace to sweeten the deal. However, Rex was able to drive a wedge between NoFace and Van Kleiss: NoFace had wanted to kill Rex whereas Van Kleiss still wanted him alive to figure out how he got his powers back, thus breaking ties with NoFace. Van Kleiss also hinted that he had something on Circe to make sure that she still remained loyal to him, but it did not stop her from quitting.
Rex accidentally activated the recall device in Caesar's pod laboratory, causing it to travel to the site of the Nanite Event, Abysus. Though Van Kleiss failed to acquire the pod, he now knew that Caesar survived the Event and intended to acquire Caesar's technology for his own twisted ends. Caesar himself described Van Kleiss as a "third rate lab hack", specifically referring to his role in the Nanite Project.
Later, Van Kleiss led Biowulf and Skalamander on an expedition into the desert to find the cause of an anti-nanite zone created by a sandstorm. Once found by Rex, he and Van Kleiss were trapped underground by a sink hole. Van Kleiss discovered the hard way that his ability to control the EVOs he created was failing. He discovered that the reason for this was that the nanites within, along with all vital elements for life, were being crushed from their bodies which was slowly turning both himself and Rex into sand.
Saying that they may die, Van Kleiss offered to tell Rex anything about the past. Rex refused, saying that he had help from someone who was actually at the Event. Van Kleiss stated that he knew it was Caesar and warned Rex not to trust Caesar, as he is not who Rex believes him to be. When Rex asked what started the Nanite Event, Van Kleiss claimed that Caesar was responsible for it. They were then attacked by sentries created from a mix of nanites and sand and they defeated them by working together.
After destroying most of the tunnels, Rex and Van Kleiss found that Zag RS was responsible for the sandstorm. Furthermore, Van Kleiss identified Zag RS as a decontamination program designed to prevent stray nanites from exiting the Nanite tank during the Nanite Project and that Caesar was the one who created it. Rex and Van Kleiss worked together and were able to defeat Zag RS. Afterwards, Van Kleiss disappeared and Caesar later stated Van Kleiss had erased Zag RS's memory when he stabbed into Zag RS's CPU. Rex felt wary remembering Van Kleiss' dire warning about Caesar.
While he never physically appeared, Van Kleiss ordered Breach to free and recruit Quarry from prison, to steal a disintegrator weapon called a Molecular Destabilizer. After Quarry was captured, Rex handed him over to Breach to be given to Van Kleiss. It's later revealed that Van Kleiss punished Quarry by smashing his body to pieces.
Van Kleiss made a cameo during the episode as one of the bidders hoping to buy EVOs from Branden Moses's enhanced EVO collection. He cut the feed from the laboratory when it was attacked by Providence.
When Van Kleiss appears, it is revealed that he had created a device that amplifies Breach's portal making abilities into portals through time. Despite this he continued to experiment on her in order to perfect the process. When Rex came to get Breach, Van Kleiss pointed out that Rex has a habit of 'saving' the Pack members from, sarcastically suggesting that Rex would try to "save" Biowulf next. After Breach left Van Kleiss, the Pack began hunting her down, eventually finding her and Rex at a bowling alley.
Van Kleiss and the Pack chased Rex and Breach throughout the city and to a park where Van Kleiss restrained White Knight by turning a nearby tree into an EVO, commenting that if White Knight knew what he was trying to do he'd get out of his way and let him.
He later had the opportunity to speak with Breach and Rex. Rex used his powers to override the shutdown on Breach's harness, allowing her to choose who to get rid of. Much to Van Kleiss's shock she sent him away instead of Rex. It is revealed that Van Kleiss built a failsafe into the harness, and Breach lost control of her powers. Both she and Rex were sucked into a portal.
It is revealed that Van Kleiss was sent to ancient Egypt by Breach's time-traveling portal. He was shown in one of the hieroglyphs that Black Knight took from the tomb which she destroyed, which indicates that he had some involvement due to the creation of the mummy-like EVO called Gharun Set and the fabled Hall of Records.
When Breach transported him through time, it was revealed that she landed him in ancient Egypt during the second kingdom era. It was also revealed that he created Gharun Set, but was forced to abandon him in that time period before Van Kleiss had a chance to destroy him. He then awakened in the second century AD where he was captured by Roman legionnaires and taken back to Rome along with his hibernation chamber where he was taken to be a gladiator. Quite quickly he was able to defeat the other gladiators and use a small amount of his remaining nanites to create an EVO out of a lion. Soon after he convinced the Roman emperor to allow him a place to work in exchange for Van Kleiss giving the Romans advances in metallurgy and tactics to ensure the Romans' growth and security. Weeks later he was forced to hibernate again before what he thought was a time anti-body could destroy him.
Every time he was forced to use his hibernation chamber it lasted less and less and he was moved around to every great civilization throughout the ages. Meanwhile, he began losing bits and pieces of who he was until he could no longer remember his own name, only knowing that he must get back to his own time both before he ran out of nanites and before the time anti-body could destroy him.
When he made it back to the present, he was practically insane because of all that he had went through. Back at Providence Headquarters, Van Kleiss was dragged down the halls by a pair of Black Pawns and unceremoniously tossed into a room to await his fate. A moment after the agents left, Black Knight entered the office and snidely mentioned that he looked terrible. She questioned whether or not he recognized her, but at first Van Kleiss seemed to be just as paranoid and unstable as before. He quickly snapped out of it upon seeing her up close, finally recovering a semblance of his former composure. He feebly mentioned that it'd been a long time.
When Providence captures Peter Meechum, one of the original scientists from the Nanite Project, they take him back to Headquarters to rejoin his former colleagues in completing their original work. Ceasar gives him a tour of the facilities, during which Meechum displays curiosity at the idea of restarting the Nanite Project. He asks who their Bio-interface expert will be, only for Rex's brother to reveal Van Kleiss being held prisoner in a room littered with several drawings depicting possible ideas for research. Peter Meechum remains disgusted at the idea of working with an enemy.
During this encounter, Van Kleiss still appears to be in a frantic and paranoid state of mind, shouting randomly at no one in particular while muttering his scientific ideas under his breath. Upon seeing Peter, he reacts with a sense of shock and nostalgia before hastily returning to his work. At the end of the episode, Van Kleiss is seen talking to himself again, although at this point he seems to have come to a new conclusion in his research.
Van Kleiss is shown again alongside the other Nanite Project scientists, the group having been sent to a Providence Research Facility in order to complete their work on the new Nanite Reactor. Due to his continued mental instability, he continues to blurt out nonsensical phrases when spoken to, although during this time his insanity doesn't appear to interfere with his ability to participate in the project.
When Rex, Six, and Jungle Cat break into this facility to kidnap the members of the Consortium, Jungle Cat attacks Van Kleiss in order to take his revenge for being turned to stone. Due to his mental health, the mad scientist does not acknowledge their past conflicts and instead begins babbling about a cat he once owned. Rex asks the other scientists if there's any reason why they shouldn't kill the former Pack Leader, but a revived Gabriel Rylander vouches for Van Kleiss on the grounds that the world still needs him. Seeing that the object of his hatred is no longer worth killing, Jungle Cat angrily tosses Van Kleiss aside. They are then interrupted by the arrival of Black Knight and a flew of Providence Agents, resulting in battle between Rex's group and the enemy soldiers.
At the end of the episode, Van Kleiss is seen wearing goggles with his colleagues as they activate the Nanite Generator. It is also briefly implied that he is faking his insanity.
While storming the Plant to take back the remaining Meta-Nanites, Black Knight managed to stop Rex by dragging Feakins onto the battlefield. She then prepares to kill the helpless teenager with a gun, but Van Kleiss steps onto the scene and stops her from shooting Rex. Although she seems annoyed with the interruption, he quickly reveals that there is a Meta-Nanite resting inside of Rex.
Black Knight seems unsure of whether of not to believe him, but has two Black Pawns sedate Rex and transport him back to the Consortium's Research Facility. Later on at the laboratory, Black Knight orders Van Kleiss to escort Rex to a chamber so they can extract the Meta-Nanite. Once Rex has been strapped down and his powers temporarily sealed off, his archenemy displays amusement towards the proceedings and mentions that Rex was always "very special" due to the secrets that had lay inside of him.
Before he can say much else, Caesar walks in and decides to speak to his brother alone. The Nanite Scientists activate the chamber to rejoin all five Meta-Nanites together, but Rex is still unaware of what exactly Caesar and the others are trying to do and struggles to prevent the fusion, and his actions do not go unnoticed by the research team.
Rylander berates Caesar for hiding the truth, and tells him to explain their true objectives to Rex, but the communication system mysteriously malfunctions. Van Kleiss is seen smirking with a broken piece of the device in his hand, having sabotaged it to prevent Rex from learning the truth. When the Consortium and Black Knight gain the power of the Master-Control Nanites, they notice several limitations and blame Rex for ruining everything.
Van Kleiss mentions to himself that neither Caesar nor the Consortium got what they wanted in the end, and seems highly amused by this. When Black Knight and the Consortium demand the full powers of the meta-nanites Van Kleiss says he can do it. Van Kleiss was then seen shaving off his beard and smiled in the mirror.He then went to the chamber in which he revealed that his insanity was just an act and attempted to absorb the power of all the Meta-Nanites. However Rex then bursted in about to attempting to stop him when Caesar says thats not necessary. Then the machine explodes destroying most of Van Kleiss' Bio-Mechanical Arm since only Rex could control the Meta-Nanites and Rex decides to cure every EVO on the planet.
Then a wave is seen spreading across the earth then suddenly Breach appears on top of a building with Biowulf and Skalamander. She then appears bringing Van Kleiss with her through a portal to an unknown place (possibly a place off earth since Rex was curing all EVOs on earth). It is unknown what became of him after this.
Cunning and manipulative, Van Kleiss does not hesitate to seize opportunities to further his plans. He is cold and ruthless when it comes to achieving his goals. If a Pack member does not comply with Van Kleiss' orders, he will turn them to stone by draining their nanites and place their petrified bodies in his garden.
Van Kleiss talks in a polite manner most of the time, even during battle or while taunting his opponents. He has a somewhat humorous side to him, as shown when he stopped in mid-battle just to ask Rex why he was "taking out his frustrations on a wall". However, Van Kleiss' polite attitude is just a way to hide the darker side of his personality, and he has been able to trick many people at first before seeing his malevolent nature.
He is an apt planner, as shown when he secretly transported nanite-infused soil under the city to make himself as powerful as he was in Abysus as he attempted to take over the UN. He keeps a level head nearly all of the time, even in a situation where the odds are against him.
He strongly dislikes Providence, stating that he does not like them meddling with his plans. He does not like the fact that people see Providence as "saviors", as Van Kleiss sees himself as the true "savior". He purposely did not announce his arrival in New York City or about his diplomatic immunity, so that Providence would attack him and his henchmen, just for the purpose of humiliating them. Furthermore, when Rex asked Van Kleiss why he always tries to destroy a cure, Van Kleiss responded that he lives off of nanites and what Providence calls a "cure", he calls "death".
After returning to his own time, Van Kleiss seemed to have a fragile state of mind. For example, when he left his pod, he was shouting hysterically that "it[Breach in a separate timestream] was coming" and ran away as fast as he could. Once, while alone, he recited what he wrote, talked to himself and yelled at no one in particular.
It was hinted several times that he was faking his insanity. This is shown before when he showed clarity while talking to Black Knight. Also, during one time, he was being threatened by Jungle Cat, he also displayed a sense of clarity before being thrown across the room. His madness is finally revealed to be a ruse, when he purposely worked to ensure that neither Caesar nor the Consortium would achieve what they desired from the Meta-Nanites.
- Environment manipulation: In Abysus, Van Kleiss was extremely powerful. As the land was seeded with nanites, he could manipulate the whole environment and summon strong roots, vines, and creepers that could grab, hold up things, and aid his movement. He could even make it rain at just one spot. He could also form roots out of his body and use them as makeshift weapons. While in Abysus, he seemed to be immortal and could regenerate himself no matter how great the wound. He was so strong in Abysus that his enemies would not dare attack him there. Providence once sent an army to save Rex in Abysus, but in the end they were all wiped-out with ease. Six was the only survivor of the rescue team. On trips out of Abysus, he was seen transporting nanite-infused soil with him. It was shown that he would die without the Abysian soil, or at least be severely weakened. His body also acted as an organic stabilizer for the highly unstable nanites in Abysus. Dr. Holiday theorized that he was bonded to them at the molecular level and as a result Rex killing him made them more unstable.
After being cured by Rex, Van Kleiss lost all of his original powers as an EVO, but claimed he still had his greatest strength: his intellect. When he reappeared later, his entire arm is bio-mechanical.
- Van Kleiss's gauntlet: The gauntlet gives Van Kleiss superhuman strength, as he was able to throw a giant, multi-ton stone slab and easily punch through solid rock. His hand is capable of extending some 10-30 feet, providing him with long-range attacks. He also has the ability to quickly fire a multitude of sharp spines from the gauntlet's fingertips. Additionally, his gauntlet is able to charge his body's nanites which enhance his physical abilities.
- Nanite absorption: Though more of a survival mechanism than a power, Van Kleiss could also use his gauntlet to drain the nanites out of other EVOs, resulting in the EVO being petrified and turned into a stone statue. The EVOs that have been turned to stone are actually alive in their petrified state, some even able to break free with concentration, and are turned to stone again when their concentration is broken.
- EVO creation: After absorbing all of Rex's active nanites (excluding the Omega-1 Nanite), Van Kleiss gained the ability to create EVOs. These EVOs are marked with a bright golden handprint where he grabbed them. The EVOs he creates are highly unstable and if not cured in time will become incurable.
- Hand-to-hand combat: Van Kleiss is also incredibly agile and fast, seen when a gladiator attacked him, he appeared behind him instantly. He is also skilled in hand-to-hand combat, defeating several well-trained gladiators with ease.
- Leadership: Van Kleiss is shown to control an army of EVOs under his command. His most powerful and elite EVOs are formed into a group known as "the Pack".
- Genius-level Intellect: Van Kleiss is shown to have an extensive knowledge on nanites, being one of the people still alive who worked in the original Nanite project. He also seems to be fluent in many different languages.
- Main article: Van Kleiss's relationships
- It was noted by Six that Providence knew about Van Kleiss and the Pack before Rex joined Providence. However, the Pack had never caused any problems up until the start of the series.
- Van Kleiss is the first character in the series to be seen bleeding.
- Despite losing his original powers, he claimed that he has retained his nanite hunger.
- Van Kleiss is revealed to know that Rex has the Omega-1 Nanite. It would seem that he knew Rex's parents very well, enough to say that Rex takes after his mother.
- The name "Van Kleiss" is Dutch meaning "of the Earth", a nod to his power over Abysus' soil and vegetation.
- In "Riddle of the Sphinx", Van Kleiss makes a brief cameo appearance in hieroglyphics. This is also shown in Cartoon Network's Action Pack comic, Hero Times Two, which was published before the episode was released.
- Van Kleiss, especially during his earlier appearances, used very little technology, using EVOs as vehicles instead of machines.
- Van Kleiss may be ambidextrous, since he can use his gauntlet and write with his right hand normally.
- Van Kleiss indirectly killed Rafael and Violeta Salazar by locking them into a room when the Nanite Event occurred, where they perished in the aftermath of the explosion.
- In "A Brief History of Time", it is revealed that he knows classical Latin.
- In Fusionfall, Cartoon Network's online game, Van Kleiss is the current (and was the final) Unstable Nano.
- It seems that Van Kleiss is quite an actor.