Profession: Ruler of Abysus
Voice Actor: Troy Baker
Van Kleiss is described as every mad scientist you ever saw only a lot freakier and dangerous. His body's molecular structure is unstable and thus has to stabilize himself using Nanites extracted from Evos captured by the Pack and experimented upon by him. He possesses the ability to control everything in his Kingdom Abysus but out of his territory he cannot use his powers. He knows a great deal about the Nanites which causes Evo Mutations and about Rex's past (implying he had a hand in his mutation), and claims that he will tell Rex everything but only if Rex joins his team.
- Achilles' Heel: He is powerless unless he is on his native soil. He spends a lot of time trying to get around this, while at the same time exploiting his own weakness so people won't think he's a threat.
- And I Must Scream: After "Lions and Lambs" Van Kleiss was sent to ancient Egypt. While there, he became aware of a cosmic presence trying to eliminate him because of his tampering with history. He decided he needed to get back to his own time, and so built a device to do so. Unfortunately, the device he used (resembling a sarcophagus) opened up way too early, landing him in ancient Rome. He repeats the process again and again, rebuilding the device in each era, each time traveling a little further into the future, constantly terrified of the presence following him. When he finally returns to the present time, it's revealed that he wasn't using time travel. The capsules he placed himself in were hibernation chambers that left him completely awake and aware while preserving his body for centuries or millenia.
- Asskicking Equals Authority: His modus operandi in a "Brief History of Time" was to fight his way through warrior ranks (largely without his powers) until everyone was convinced he was a god, and then to commandeer a lab and revolutionize the local civilization until technology was good enough for him to make a Not!Time Machine. It was implied he did this multiple times over 4000 years.
- Attack of the 50-Foot Whatever: Between being brought Back from the Dead and Brought Down to Normal.
- Badass Longcoat: He wears a pretty badass brown longcoat.
- Bad Boss: When the newest member of the Pack cripples Van Kleiss' nanite suit, he petrifies the Evo on the spot.
- Batman Gambit: All of his plans, most notably when he takes over New York.
- Beard of Sorrow: Sports one after his numerous And I Must Scream stays in his hibernation chamber. As befitting the trope it makes him look haggard and weary and when he reveals that he's still a bad guy he makes sure to give himself a shave first.
- Been There, Shaped History: It's heavily implied that legends of monsters across several mythologies were actually EVOs Van Kleiss created to serve him while voyaging through the past; we see him transform a lion into a Chimera-like behemoth in the Roman Colosseum, at the very least.
- Big Bad: Of the first and second season.
- Brought Down to Badass: "A Brief History of Time" has him with limited use of his powers for the episode. Despite this, he is shown to be a very badass warrior. Enough to eventually gain control over the local kingdom. On multiple occasions. In multiple eras.
- Brought Down to Normal: When Rex is forced to activate a machine that resurrects Van Kleiss, he makes alterations that render him curable. Van Kleiss is not pleased, but declares that he still has his most powerful weapon intact: his intellect.
- Came Back Wrong: Leaving him curable.
- Cloudcuckoolander: Following his And I Must Scream incident. It's just a facade, though.
- Control Freak: As Rex points out at least once, Van Kleiss has to be in charge. This has actually ended up scuppering his plans on a couple of occasions, not least because of the lack of faith it implies in his subordinates.
- Demoted to Dragon: In Season 3.
- Yet he tries to pull a Starscream in the finale, but it failed.
- Discard and Draw: He lost his powers when Rex cured him, so he took Rex's nanites, giving him new powers. New powers that allow him to leave Abysus without any impairment.
- Evil Genius: The sheer scope of his knowledge, scientific or otherwise, is incredible. He was apparently a programmer of some sort while working with Cesar, but he displays mastery of metallurgy, weapons crafting, quantum and relativistic physics, electrical and mechanical engineering, all kinds of biology, ancient dialects of multiple linguistic families, anthropology of ancient civilizations, and infrastructure development on a grand scale. In most of these, he has complete and total mastery, as he is able to develop those fields past modern levels from first principles.
- Emperor Scientist: He is the ruler of Abysus and formerly worked on the Nanite Project.
- Empowered Badass Normal: Somewhere between "scientist", "ruler", and "EVO vampire", he found the time for "absolutely badass swordsman."
- Faux Affably Evil: He may act like a perfect gentleman, but at the end of the day he cares only about himself.
- From Nobody to Nightmare: According to Cesar, he was a minor lab technician before the Incident. Cesar turns out to have been understating his importance, but nevertheless he was hardly at the forefront of the project.
- Genius Bruiser: While Van Kleiss has always been a formidable opponent, it could usually be attributed to his powers and/or plans. However, "A Brief History of Time" shows that, when powerless, he is an extremely good fighter. In each era and location he visited, it seems he became a warrior of some sort(a gladiator in Rome, a Samurai presumably in Japan, etc.), and even knew the local language fluently, bumping him up to near-Crazy-Prepared.
- Genius Loci: Rex outright states that he is Abysus, and not just controlling the land.
- Good Thing You Can Heal: His original powers allowed him to regenerate from the land around his palace, no matter how badly injured. He presumably lost it once cured.
- Green Thumb: While on Abysus, he can control giant roots out of the ground.
- Hijacked by Ganon: Goes for it in the end, after manipulating damn near everyone.
- Humanoid Abomination: For an EVO, he looks fairly human.
- Important Haircut: Averted, He didn't cut off his hair, But he shaved off his beard instead.
- Joker Immunity: But justified by his being nearly impossible to kill. Lately, he's just a lot more careful.
- Manipulative Bastard: He's very good at this. While his latest scheme, a contingency plan to force Rex to resurrect him in the event of his own death, backfired pretty hard, he still ended up a lot better off than he would've been without it. By definition, since you can't get much worse off than being dead. As of episode 21 however, Van Kleiss may just met these qualifications. While Rex gets his powers back after Van Kleiss absorbs Rex's nanites, Van Kleiss still has Rex's nanites, and the power to make any human being he wants into an Evo.
- Mythology Gag: When Van Kleiss gets sent back in time 4000 years, one of the stops that he makes is in Ancient Rome where he is a gladiator in the arena; one of the many challenges he faces that earns him his freedom is fighting with a Lion: which he transforms into a Chimera that served him. Those well-versed in mythology can see the direct parallel to the story of Androcles and the Lion.
- Obfuscating Insanity: As revealed in the series finale when he attempted to pull a Ganon-style hijacking.
- Omni Disciplinary Scientist: He certainly has the greatest scope of knowledge of any scientist in the series, though he's not necessarily as successful on the cutting edge.
- Omni Glot: "A Brief History of Time" shows that he knows a lot of different languages, and even specific dialects therein.
- Our Vampires Are Different: Nano-vampire, technically, before being cured. Still has some vampiric traits.
- Out-Gambitted: His plan was to gain the Meta Nanites for himself was foiled long before he even had the chance to get them.
- No Name Given: We're never given his first name. Three seasons, 60 episodes.
- Power Parasite: After getting depowered by Rex, Van Kleiss stole Rexs' Nanites and depowered him as a result. He gets powers opposite to Rex's — creating Evos.
- President Evil: He's the legally recognized ruler of Abysus, which he exploits particularly in the seventh episode by invoking diplomatic immunity—and it works until that little business with holding the UN hostage...
- Psychotic Smirk: Loves to give off a lot of these.
- Put on a Bus: Twice. It takes about a half-season for him to return each time.
- Royals Who Actually Do Something: By implication. He's been a legally recognized ruler for some time, but seems to have been a professional researcher since before the nanite event.
- Skunk Stripe: Two on both sides of his bangs.
- Well-Intentioned Extremist: He claims to be merely working to create a better future for all EVOs, but we don't know how much he really buys into that, and how much is just propaganda. It's propaganda. He's been going for omnipotence since before the start.
- You Have Failed Me: Does this to Jungle Cat in "Dark Passage" after he damages Van Kleiss's soil circulation suit.
- You Killed My Father: At the end of the series, it's revealed Van Kleiss was the one who killed Rex's parents by locking them inside the nanite reactor room by damaging the device's hatch before it exploded.
Profession: Leader of The Pack
Voice Actor: Troy Baker
An armored werewolf-like Evo with super human abilities, Biowulf is fiercely loyal to Van Kleiss. Due to Van Kleiss powers being limited to his native soil, Biowulf acts as the Pack's de facto leader.
- Affably Evil: He's quite gruff and cold most of the time, but after quite a while, he's mellowed somewhat.
- Defeat Means Friendship: With Rex, during 'Assault on Abysus'. The battle was largely ceremonial, though, and it was implied that he was already willing to give Rex a fair shake.
- Dragon Ascendant: After Van Kleiss disappears he becomes the Pack's new leader.
- The Faceless: He's constantly wearing a metallic wolf mask, so we never see his real face.
- Mistreatment-Induced Betrayal: He helped Rex and Circe escape and he's beginning to lose his loyalty to Van Kleiss after the way he treated him.
- Mysterious Past: Nothing is known about him before he joined the Pack.
- Noble Top Enforcer: Not apparent at first, but by Assault on Abysus, he has set up Abysus as the last safe Haven for E.V.O.s, reasoning that they have the advantage there, and Providence won't attack them while they do have the advantage, Providence proves too big and powerful to stop.
- Noble Wolf: A wolf like warrior that is very loyal to Van Kleiss and has a pack mentality.
- Reasonable Authority Figure: After taking over from Van Kleiss. He still needs to get over his habit of picking fights with other organisations' envoys (although maybe that was just because it was Rex), but otherwise, he's doing pretty well.
- Red Eyes, Take Warning: The eyes on his wolf mask are red.
- Sycophantic Servant: While not as apparent as other examples, he becomes very defensive when he believed his role as Kleiss' #1 minion would be taken from him.
Profession: Member of The Pack
Voice Actor: Hynden Walch
Breach can open portals from anywhere to anywhere else, making her the Pack's main form of transportation. In addition to that, she can also fire the portals at her enemies like shuriken and send attacks through them. With these Evo powers and Breach's insanity, make her the Pack's most unpredictable member.
It was later revealed that she took the city of Greenville, OH and turned that place into her personal dollhouse. She uses this "dollhouse" to keep "shiny things" and have captive EVOs fight each other.
- And I Must Scream: Is forced to follow Van Kleiss through time for six thousand years until Rex manages to free her.
- Blinding Bangs: Her hair usually covers both eyes.
- Blue-and-Orange Morality: Outwardly, it seems like she's just a Psycho for Hire mook. It turns out that she's doing it for neither money nor Van Kleiss' vision of world domination (though she pays that lip service). She for some unfathomable reason seems to pick "favorites" to whom she'll be predisposed to trust. In Van Kleiss's case, it manifests as devotion, to the point of withstanding abuse and torture. All of which she justifies with an absolutely skewed sense of reality.
- Collector of the Strange: Her "dollhouse" has Evos, Creepy Dolls, and ice cream trucks.
- Not to mention the dollhouse itself is Greenville, Ohio.
- Dark Chick: For her twisted sense of emotions and strange attraction to Rex.
- Fire-Forged Friends: With Rex in "Lions and Lambs".
- Hidden Eyes: Constantly in use in her earlier appearances, and frequent even once her face was shown.
- HeelFace Turn: Though left ambiguous in the end, as she's last seen rescuing Van Kleiss and the Pack in the Grand Finale, but it's unclear whether she's helping them or planning on getting some payback.
- I Just Want to Have Friends: She tells Rex how glad she was he was a friend to her, and gives him a hug before she vanishes into the time portal.
- Living Doll Collector: Likes to "collect" people to put in her pocket dimension as playthings.
- Mind Screw: Her portals can lead to other dimensions, complete with altered physics and trippy space imagery (possibly also a part of her mind). A lot of the things she says in "Lions and Lambs" counts.
- Multi-Armed and Dangerous: She has four arms.
- Sanity Has Advantages: If she wasn't so childish and crazy, she'd be far more dangerous than Van Kleiss.
- Stringy-Haired Ghost Girl: Definitely based on them.
- Super OCD: Do not mess with anything in her dollhouse dimension.
- Tears of Blood: Well, not so much blood as blood-red portal energy, but when she starts to break down after Rex has shattered her fragile mind, her skin flakes off in the pattern of tears to reveal glowing red energy beneath.
- Thinking Up Portals: Her main power, which she spams for all it's worth.
- Villainous Breakdown: Goes through this a few times throughout the series.
- Wall Crawl: While she doesn't get much mileage out of it due to her portals being far more useful, Breach has been shown to be able to cling to walls.
- Yandere: She's quite fond of Rex, but very unhealthy about it. Rex seems to think its a romantic thing, but Breach's perspective on the situation isn't entirely clear. The episode "Breach" makes her interest in him very childish, seeing him as a new and interesting toy she picked as her new favorite.
Profession: Member of The Pack
Voice Actor: John DiMaggio
A humanoid lizard Evo with crystal spikes growing out from all over his body and a crystal club growing out of his left arm. He can fire said spikes out of the club or grow it into a shield, providing short or long range attacks, as well as defensive abilities.
- Body Horror: His head appears to be stuck pointing up and to the side.
- The Brute: Played With. Though he's definitely the team muscle, he's less aggressive than he looks and actually tries to keep the peace between the Pack and Providence at the beginning of Leader of the Pack.
- Dumb Muscle: He's clearly not the most articulate member of the Pack.
- Enemy Mine: With Rex and Circe in Assault on Abysus It doesn't end well.
- Mysterious Past: Nothing is known about him before he joined the Pack.
- Reptiles Are Abhorrent: He's a giant, twisted, perpetually-drooling evil lizard-man.
Jungle Cat is an EVO that was seen having joined The Pack shortly after Breach's disappearance, and helping Van Kleiss look for Dr. Rylander's laboratory. He accidentally cuts one of the pipes providing Van Kleiss with Abysus. He was drained of nanites by Van Kleiss, and turned to stone...Amazingly, it did not take. He has now joined Providence, hoping to get revenge on Van Kleiss.
- Boisterous Bruiser: On one occasion, he's dealing with a pack of Providence grunts when he spots Black Knight about to take one of the Meta-Nanites. He beans her with a Providence soldier to stop her. Cue epic victory pose.
- Determinator: He can overcome the petrification Van Kleiss imposed on him by sheer willpower.
- In-Universe Nickname: Rex refers to him as "the cat".
- Mistreatment-Induced Betrayal: Attempted murder tends to have that effect.
- Not Quite Dead: What should have been a fatal Taken for Granite attack leaves Jungle Cat alive, but he reverts to stone if he loses focus.
- Not So Above It All: He comes off as a super-efficient hardass, a la Six, but he's got an eccentric sense of humor.
- Revenge: Wants it on Van Kleiss, but he's reasonable enough not to let it completely control him.
- Superpower Lottery: Were it not for the outward mutation, he'd have hit the jackpot. Strength, speed, claws, cloaking, voice mimicry; he's got the complete package.
- Taken for Granite: He gets better. Sorta. If he loses his focus, he goes back to stone, until he wills himself back to life again. He can also use this to his advantage though, because stone is tougher than even his nanite-enhanced flesh.
- Voice Changeling: Revealed in his second appearance.
- What You Are in the Dark: Couldn't bring himself to murder Van Kleiss in revenge, probably because Van Kleiss had recently been traumatized into insanity.
- You Have Failed Me: Van Kleiss casually murders Jungle Cat for damaging his nanite dirt suit. Unfortunately for Kleiss, it didn't take.