It's me, Caesar. Your brother!

–Caesar to Rex, "Mixed Signals"

Caesar Salazar
Caesar Profile
Vital statistics
Name Caesar Salazar
Species Human
Affiliation(s) Nanite Research Team (formerly)


Physical description
Gender Male
Hair color Black
Eye color Dark brown
Abilities  ·Genius-level intellect
 ·Nanite expertise
 ·Skilled inventor
 ·Hand-to-hand combat skills
Weapons Electromagnetic devices capable of rendering people unconscious
Nanite-tracking devices
Dimensional disruptor
Relatives Rafael Salazar (father)
Violeta Salazar (mother)

Rex Salazar (younger brother)
Abuela (adoptive grandmother)
Alpha ("son"/creation)
Zag RS ("daughter"/creation)

Allies Rex Salazar, Dr. Holiday, Agent Six, White Knight, Gabriel Rylander, Peter Meechum
Enemies Van Kleiss, Alpha, Consortium
Further info
First appearance "Mixed Signals"
Last appearance "Endgame, Part 2"
Portrayed by: Freddy Rodriguez
Images | Quotes

Caesar Salazar (pronounced as the Spanish variant César) is Rex's older brother and one of the surviving scientists of the Nanite Project.[1]


Early life

Caesar was born and raised in a small remote town where he went to school and received a basic education. Since he was a kid, he was distinguished by his extraordinary inventiveness.[2] At some point Caesar and his parents, Violeta and Rafael Salazar, had been traveling all around the world. After Rex was born, the whole family settled in Geneva, Switzerland.[1] However, he and Rex kept coming back to the small town for summer holidays.[2]

Later Caesar, alongside his parents, started the nanite research team in Abysus. During the research, the scientists divided into groups, each having different ideas about how to use the power coming from the nanites. During the Nanite Project, Caesar created two artificial intelligences that later went rogue and threatened all life on Earth: the control nanite Alpha and the decontamination program Zag RS.[3][4]

Due to an unfortunate event, ten-year-old Rex was gravely hurt and only an infusion of active nanites could save him. Yet the successful operation did not convince the others to change their plans.[1] One of the scientists sabotaged the project, which caused a massive explosion, and it was Rex's new powers (which were most likely a side-effect of the previous infusion) that saved Caesar and Rex during the Nanite Event.[5] Van Kleiss stated it was Caesar who caused the Nanite Event.[3] It was later revealed that Caesar and his colleagues released the nanites, believing it was the only way to save the world.[6]

Just before the explosion, Caesar fled to his research pod and activated its subspace engines to get away. The engines were supercharged and launched the pod into orbit at super speeds. The speed he was traveling at was so great that in the fifteen minutes it took to take control over the machine, five years had gone by in the rest of the world.[1]

Season Two

Mixed Signals

Caesar Mixed Signals

Caesar pilots his research pod.

After returning to Earth, Caesar's first priority was to find Gabriel Rylander since Rylander was in charge of looking after the Omega-1 Nanite. He sent a schematic of a transmitter to the nanite which, since it was inside Rex, caused it to build it for Caesar to trace it.

Unaware that his younger brother had the Omega-1 Nanite inside of him, Caesar traced the transmitter and came across Rex, who was shocked and confused. After a greeting and hug, Caesar instantly reacted protectively, ignorant of Providence's intentions and relations to Rex, and attempted to get his younger brother to "safety". Rex agreed to go along with him despite Dr. Holiday's, Bobo's and Six's initial hesitance, so Caesar took him out of Providence to his own lab.[1]


Caesar appeared briefly when Rex came to his lab, needing his help. Seeing his older brother was currently working, he asked if it had something to do with nanite research. Caesar only replied casually that he was making mango smoothie with a hyper-electromagnet that could disassemble a tank from a kilometer away.

Rex then asked Caesar to set up a haunted house with his technology to scare Annie and Claire. While Rex thought of a simpler method, Caesar offered another extreme way. Caesar later appeared again as Rex and the group left the haunted hotel. He brought a holographic trap for the haunted house, reporting to his younger brother that it had a battery problem. Rex then introduced him to his friends as the cause of the effect besides the EVO cat.[7]

Written in Sand

Caesar is mentioned by Rex when he was trapped in a sandstorm with Van Kleiss. Rex told him that he already had someone he could trust who could tell him of his past, his own brother. On the other hand, Van Kleiss disagreed, saying that Caesar could not be trusted and may not be who Rex thinks he is.

Dr. Holiday reported to Caesar, informing him that they hadn't found Rex. Being too focused on his work, Caesar forgot his missing brother. After an apology he said that Rex naturally produces selenium like dandruff. Thus they used this new way to find him.


Caesar explains about his creation, Zag RS.

After Zag RS had been defeated, Caesar explained that he did indeed design Zag RS. However, he didn't understand why it had evolved into a "sentient nanite slayer" as he put it. Caesar then rebooted Zag RS to figure out how the Nanite Event really happened, but Zag RS' memory had been erased. He said Van Kleiss must be the cause of it, though Rex suspected otherwise, remembering Van Kleiss's advice about not trusting Caesar. When Rex insulted Zag RS' voice, Caesar was disappointed that Rex didn't recognize it. He then explained that Zag RS' intention was for safety, protection, and caring. Then Caesar revealed that the voice had belonged to their mother, Violeta Salazar, much to Rex's shock.[3]

Night Falls

Caesar and Rex visited their adoptive relatives in a small village in Mexico, flying there in his research pod. When they arrived, he and Rex met Esteban, Caesar's classmate who had become mayor of the town. He was warned by Esteban not to visit Abuela, their non-blood related grandmother, though Caesar shrugged off his warning. Before he and Rex got inside the small village, Caesar explained that they used to spend their summer in that village. Rex wished to remember all of it and then Caesar comforted him, saying Abuela would be happy to see him.

During the night, when he stayed in the room with Rex, he was the first to figure out Federico's disappearance and demanded answers from Abuela. After they discovered the community's habit of changing into EVOs during the night, Caesar tried to find a cure for them and succeeded. He was later seen celebrating the victory over Hunter Cain with the rest of the town.[2]

A Family Holiday

Caesar ran stress tests on Rex in the absence of Dr. Holiday, adding two EVO bloodhounds to the mix. Later he had, what Bobo and Rex described as, a "fangirl" reaction to Dr. Branden Moses who he described as one of the leading researchers in nanite research. He was also shown to be oblivious to the attractiveness of Dr. Holiday.[8]


Caesar's robot

Caesar's large invention.

In his laboratory, Caesar seemed intent on working on a giant metal robot that shot out bright purple energy blasts. It shot an energy ray at the group, but Rex technopathically closed the door before it could do any more damage. The second time Diane opened the door, one of Caesar's feet was pulled by the energy ray and he was hung upside down.[9]

Lions and Lambs

After Rex and Six returned and reported Breach's new device, Caesar examined it and said that he could learn more if they had it. In the future, Caesar was the only one in Rex's circle of friends who did not quit Providence following his younger brother's six-month absence. He also noticeably sported a goatee. He appeared to be happy to see Rex again (as he gave him a brotherly hug), but refused to explain what was really going on to his younger brother and preferred to show him to Black Knight.[10]

Season Three

Back in Black

Rex fled from Black Knight's office and crashed into Caesar. Annoyed by his sudden behavior because his coffee was spilled, Caesar asked what happened. Rex blabbered that he believed he was in a different dimension. He pinned Rex to the wall and convinced him that this was not a different dimension. Instead of calming down, Rex panicked and believed it was another universe and this Caesar was his older brother's evil twin while grabbing his chin (referring to his beard) and then ran again. Caesar then followed Rex in the Petting Zoo with Black Knight, explaining about the changes that were seen in the new Providence.

Rex and Cesar

Rex argues with Caesar.

Later, it is revealed that Caesar had been the one who had invented the white collars that give mind control over the captured EVOs, which makes them act more obedient through remote control. When a suspicious Rex found out the truth about using brainwashed EVOs to do his and Black Knight's bidding, they had an argument regarding morality. Rex preferred the old way through combat, while Caesar still thought his way was the best. When Caesar decided to leave because he wanted to return to his work, Rex began crashing his lab with his Smack Hands. Caesar begged his younger brother to stop.

Caesar later decided to use his mind-controlling machine on Rex after seeing that there were no alternatives. It took longer to control Rex because he was resisting. Caesar pleaded to Rex not to resist because it would hurt him. Black Knight, who was running out of patience, ordered him to raise the power level on the mind-control device in order to gain Rex's compliance. Caesar was hesitant, saying it was not safe, but obeyed when she said it was for the best. Rex rebelled and destroyed the mind control device using his Punk Busters. When his younger brother fled, Caesar reported to Black Knight that he had a backup. It was the prototype, which was not portable, but still had enough power to control Rex. Black Knight had ordered him to get the machine ready.[11]

Black and White

Rylander Caesar Rex - Black and White

Caesar attempts to revive Gabriel Rylander.

White Knight revealed his photos from his research on spying the new Providence. One of the pictures revealed Caesar and Black Knight had been taking out machines from Rylander's laboratory. It dawned on the group that the new Providence wanted to restart the Nanite Program. When Rex infiltrated the new Providence headquarters, he visited Caesar's lab for a while, hoping to get an explanation from his older brother. It was revealed that Caesar attempted to revive Rylander with the same method that Van Kleiss was revived. However, Caesar's effort wasn't perfected as Rylander's form was still incomplete.

Caesar then revealed that he was not interested in working under Black Knight's order from the beginning, that he led the restarted Nanite Program for his own goal: to fix the Event. He then admitted to Rex that he and his colleagues had released the nanites, thus starting the Nanite Event. Feeling angered, Rex asked his reasons, as Caesar answered it was the only way to save the world. Before Caesar could explain it further, they were interrupted by EVO hounds.

After defeating all of the hounds, Rex took out the data rod and downloaded Caesar's data. Caesar and Rex exchanged glances when he took off with his Boogie Pack, escaping the headquarters. Rex later learned that the Event was triggered to keep the god-like power of the Meta-Nanites out of the Consortium's hands and thus he came to forgive Caesar.[6]

Ben 10/Generator Rex: Heroes United

Caesar was trying to figure out the space-time rift where Ben Tennyson had arrived along with an unidentified mechanical creature. He hung up on Black Knight and decided to investigate it himself. With his ship, he hovered above Dr. Holiday and Agent Six who were observing a part of the mechanical creature. He said he would help them but would inform what it was later as he grabbed the part and returned to the Keep.

Alpha caesar rex - heroes united

Meeting Alpha.

Back in his lab, Caesar was soon shocked to learn that the creature was none other than Alpha, another of his own creations. He drove his ship in front of Ben and Rex and tried to destroy Alpha once again with a dimensional disruptor to send it back to the Null Void. He was unable to do so because Ben as Diamondhead had destroyed it. They thought Caesar was going to shoot his younger brother. Caesar then pointed at Alpha who appeared in front of them. He wasn't pleased to see his past creation, who called him his "father". Alpha asked for his help but Caesar rejected his request.

After the Alpha Nanite was defeated and contained by Rex and Ben, Caesar came to retrieve the Omega Nanite from Alpha. Not having time to fully repair the dimensional disruptor, he was not sure how long it would hold, and told Rex to tell Ben goodbye so that he could return to his own world and drop the Alpha Nanite back in the Null Void. Caesar was seen at the end, suddenly appearing at the The Plant to re-inject the Omega Nanite back into his younger brother's body. Rex asked if he had picked up the Alpha by mistake. Caesar reassured him by saying that nothing is one hundred percent.[4]

A Brief History of Time

Caesar was given the task of locating Van Kleiss under the orders to arrest him and bring him in once he was found.

Mind Games

He was working to regather his surviving former colleagues to restart the Nanite Project. He also had Van Kleiss under his watchful eye and had a private conversation with old colleague, Peter Meechum, about the situation.


He talked to Rex about the Salazar ranch and some old notes and equipment left in there that could be of use to him in his work.

Target: Consortium

Endgame, Part 1 and 2


Rex Caesar Mixed Signals

Rex and Caesar.

Caesar's personality is akin to that of a mad scientist, coming off to Rex and the others as a tad out of sync from reality. However, he seems to be aware of his own eccentricities as demonstrated when Rex asked him, "Are you crazy?!" to which he replied, "Depends on who you ask." He occasionally talks off subject, is easily distracted, does not seem to listen when spoken to directly and is sometimes forgetful in daily activities. For example, while he and Rex were trying to escape from Abysus, out of nowhere he asked Rex if he would like to see a photo of them and their father, Rafael.[1]

Caesar is also very upbeat, curious and overprotective of his younger brother. In fact, it seems some of Caesar's less "weird" traits are shared with Rex, such as his sense of humor and loyalty.

Despite his logical, scientific tendencies and mentality, Caesar does show an open-minded side, apparently believing in the String Theory enough to try and create a Null Void projector. He was even willing to consider the possibility of Ben's watch being of alien origin.

Caesar seems to be fearless, as demonstrated when he stood in front of many EVOs without worrying about being harmed. Thus far, it seems that he is generally not afraid of anything, as made apparent by not only the EVO situations, but the way he barged into Providence without worry.[1] He also isn't afraid to go up against stronger men like Agent Six or Hunter Cain to defend Rex even though he is not technically a combatant.

Although he was sometimes willing to go to great lengths in the name of science, Caesar was not without moral restraint. This is shown when he put control collars on EVOs as with Black Knight the only alternative was death. Another example of this is when he chose not to reveal the location of Rex's team to Black Knight. He even gave Rex back his Omega-1 Nanite, proving that he trusts Rex more than Black Knight.

Physical appearance

Caesar is a tall man in his early twenties. Being half-Mexican and half-Argentinian, Caesar has a darker skin tone, brown eyes and dark hair which seems to be naturally spiky. His facial features are similar to Rex's, only more angular, with the addition of small lines near his eyes. Caesar wears a khaki vest with a green long sleeved shirt underneath and green pants. He also wears heavy, military-like boots. When working in his lab he wears safety goggles.[3] Before the Nanite Event, he wore a blue dress shirt with a red tie under a white lab coat.[1]


209-Caesar mango

Caesar testing out his inventions.

  • Inventing skills: As a skilled inventor, Caesar can build his own unique devices to defend himself, such as a sonic-wave handheld device that can knock people out. He has his own mobile high-tech lab from the original Nanite Event which contains a huge collection of inventions from the initial portable Abysus lab.[1]
  • Genius-level intellect: Despite having no knowledge of the last five years, Caesar still trumps other scientists with his knowledge about the nanites, as he was the one who contributed to and worked on the original Nanite Project with his parents, Rafael and Violeta. He was the only known person besides Van Kleiss still alive that took part in the project, before information of the Consortium was revealed. Being exceptionally skilled as a fast and hard worker, he told Holiday that he had done about five-hundred tasks in fifteen minutes.[3]
  • Hand-to-hand combat skills: Although Caesar knows how to fight, he has normal human strength and is unable to take down opponents stronger than himself.[2] Instead, he often relies on his inventions to defend himself.


Rex Salazar

Salazar brothers

Rex and Caesar.

Caesar seems to care greatly about Rex, often calling him mijo, a Spanish word of endearment. On the other hand, Rex's feelings about his older brother seem mixed at first. While he was happy to have found his long-lost brother, he stated that Six, Holiday, Bobo, and the rest of Providence were the ones he had a family-like connection with. Rex also was warned by Van Kleiss that Caesar is not the man he believes him to be.[3] Rex seemed to ignore this warning, as he traveled with his older brother without worry and became used to his older brother's eccentricity. Caesar also taught Rex about his forgotten past, such as how he and Federico became the "Cabezas de Trapos".[2]

After the six-month time-skip, Caesar is shown to have developed extreme views when dealing with EVOs, and is willing to exert control over them using a new invention in order to achieve unknown ends. When Rex found out about this new approach and protested against it, Caesar responded by attempting to use the mind-control device on him. Although he showed signs of hesitation to harm his brother, Caesar decided that it was for the best and joined in Black Knight's efforts to capture and control Rex.

Their relationship deteriorated more after Caesar told Rex that he had intentionally caused the Nanite Event to save the world. Afterward, Rex destroyed his lab and downloaded all of his research that was left. At the end of this encounter Rex told Caesar they were done. Though soon after back at the Plant, White Knight revealed that if it wasn't for the Nanite Event, the world might have been destroyed, or worse, which mended their relationship a bit.

Although Caesar knew of Rex and his team's location, he did not reveal this information to Black Knight. He also gave Rex back his Omega-1 Nanite instead of keeping it in his lab or alerting Providence, showing that he trusts Rex more than anything.

When Rex went back for the Jungle Cat, he encountered both Caesar and Peter Meechum. Rex wondered why there was no reason for the Jungle Cat to put Van Kleiss out his misery. Dr. Rylander then vouched for Van Kleiss, saying that the world still needs him. Caesar assured Rex that they were doing the right thing, but his younger brother no longer believed it. Dr. Rylander then told Caesar to tell Rex their true intentions, but before Caesar could do so, they were interrupted by more arrivals.

Rex eventually came to understand Caesar's true intentions, and after Rex used his new found powers to reprogram the nanites, the brothers ultimately reconciled.

White Knight

White Knight has expressed his interest in Caesar, stating that the man could be of use to Providence with his extensive intellect and knowledge on nanites. As Six considered Caesar a liability, it made it all the more reason to keep him with Providence.[1]

During the course of time White Knight started to view Caesar (or more likely his failed experiments) as a nuisance, sarcastically calling him a "genius".[10]

Agent Six

Six believed that Caesar would be more of a hindrance and a major liability than an assistance to Providence due to his involvement in the original Nanite Project.

Rebecca Holiday

Caesar, to Rex's confusion, does not share the same impression as him and seems to be indifferent to Holiday's "hotness", noticing only her bright intellect.[8] However on their first encounter, Caesar was aware of Dr. Holiday's attractiveness and called her bonita which is Spanish for beautiful.[1]

Van Kleiss

Caesar showed disdain towards Van Kleiss, describing him as a "third-rate lab hack". The feelings are most likely mutual, as Van Kleiss was shown to be irritated by Caesar's unexpected return. Despite this, Caesar seems to have some respect for Van Kleiss' scientific skills, going as far as complementing the device that enhanced Breach's abilities and allowed her to travel through time.

Later on, Caesar was under orders from Black Knight to apprehend Van Kleiss and turn him in. After his capture, Van Kleiss was put under Caesar's watchful eye despite the risk and liability he carried.

Zag RS

Caesar is the original creator of Zag RS, which was initially designed to be a nanite decontamination program at the nanite laboratory in Abysus before the Event. Zag RS is also revealed to have the voice of Rex and Caesar's deceased mother, Violeta Salazar.

Black Knight

Black Knight seems to trust Caesar to an extent due to his involvement in the original Nanite Project, allowing him to play a large role in the formation of New Providence. They have the same views on several aspects of their work, such as their methods of dealing with EVOs. Caesar is quick to obey Black Knight's commands and does not question them.[11] However, Caesar is not really interested in working for Black Knight, as he admitted to Rex, "I'm not helping Black Knight do anything, I'm trying to fix things." He only stayed at Providence to work on fixing the nanites and containment of dangerous EVOs.


Caesar is the original creator of Alpha, which was initially designed to be a control nanite. After Alpha eventually became rogue and began an attempt to take over living bodies, Caesar took quick action and sent Alpha to an empty space which was actually the Null Void, an intergalactic prison used by the Plumbers of Ben Tennyson's universe. Alpha considered Caesar as his father.


Season One

Season Two

Season Three


Video Games


  • He is Rex's only known living blood relative.[1]
  • Caesar has easily invaded Providence.
  • The meaning of his first name is similar to Rex's name, as both essentially mean "Ruler". "Caesar" also means "Head full of hair" in Latin.
  • Caesar pronounces his name "See-zer" when talking to Black Knight, and "Cézar" when talking to Rex.[1][12]
  • In "Exposed", when he has clearly lost control of what appears to be a volatile and potentially dangerous experiment, Six merely closes the door and moves on, suggesting that this sort of thing is not uncommon for Caesar.
  • It has been hinted he can unintentionally communicate with Rex through his nanites.[1]
  • He says it makes him laugh when Rex tries to speak Spanish, because Rex often mispronounces the language.[1]
  • He sometimes calls Rex mijo which is his word of endearment. Mijo is an abbreviation of mi hijo, which in Spanish means "my boy". Although mijo commonly means "my son", Caesar uses this affectionate term to refer to Rex as his junior male not directly as his son.[1]
  • Due to being in his twenties (and not aging for five years while trapped in sub-space), he would have been at least ten-years-old when Rex was born.[1]
  • Caesar was the first character ever shown sleeping in clothes different than what he wears every day.[2]
  • Caesar and Rex have adoptive relatives in Mexico.[2]
  • Although having no amnesia, Caesar has an information gap due to his five-year absence in sub-speed caused by the explosion at the Abysus research facility.
  • Caesar is known to have a unique taste in food, especially pizza, with his favorite topping being salmon and pineapples.[1] He also enjoys smoothies.[7]
  • During Rex's six-month time skip, Caesar grew a beard, but he shaved it off soon after Rex's re-appearance.[10]
  • Caesar's behavior and social skills indicate he could have ADD or ADHD.
  • Over the course of the series, the age gap between Rex and Caesar has closed by four and a half years, Rex got five years older when Caesar was stuck in sub-space and Caesar got six months older after Breach sent Rex into the future.
  • Caesar claims that his ship moved at such speeds that fifteen minutes for him lasted five years on Earth. In order for this to be accurate, his ship's velocity would have to be at least 99.9997% the speed of light.