Benjamin Kirby "Ben" Tennyson is the titular character of Ben 10: Heroes of Evolution.
Ben is still 16 years of age and has lived through the canon of the first three Ben 10 series, with the omission of his receiving the new Omnitrix from Azmuth in The Ultimate Enemy, Part 2. He is still in possession of the Ultimatrix. His life as chronicled in Heroes of Evolution takes place in the summer of 2014, with him having finished his sophomore year in high school and on the verge of becoming a junior.
In "Pilot - Part 1", Ben is finishing his last day of his 10th grade year at Bellwood High School. With Julie, he tries to escape high-energy fans following endless partying at school, but is saved by BPD Captain James Rozum to discuss Will Harangue's newly-initiated criminal activity. After Rozum gets a text that seems to frighten him, Ben comes back the next day with Gwen and Kevin and learns that the perpetrators behind a shooting were military men; Rozum's brother is in the military and such a disgrace disgusts the captain.
Ben, Gwen and Rozum track down the perpetrators, but Ben is ambushed and defeated even despite his use of Humungousaur. Kevin and Gwen are captured separately, and Harangue comes in to make a large report. Ben is taken to Fort Briggs, which belongs to military general John Briggs. There, Briggs betrays Harangue to try experimenting on Ben and use the Ultimatrix's energy for a prototype gun he's building.
Briggs is revealed to be working for Vulkanus, who kills him. Ben, his team, Grandpa Max and Cooper Daniels all chase Vulkanus to Bellwood with a captured Harangue - Ben defeats both Vulkanus and an escaped Harangue and attracts media attention with his return. He promises his parents and friends that hero time is never over. Elsewhere, a mysterious man using a voice scrambler calls Vulkanus in jail to lament his failures.
In "Brothers", Ben's time with his friends is shown a little more. Ben and Kevin save Ben's parents from being killed by two assassins sent after Ben: Krill and Wyatt Herman. Gwen arrives to assist them and they take the battle all the way to the bridge leading to the city.
Max calls Ben to brief him on the perpetrators and their history with him as students. Ben is surprised by this and interrogates Krill and Wyatt - they say that they were Plumbers and were set up to fail a hostage rescue by an anonymous man hiring them to be hitmen.
The same superior (who also hired Vulkanus) texts them, asking for a report. Ben texts back and threatens the man despite Krill and Wyatt's pleas not to, but realizes his grave mistake when he is sent a picture of the brothers' parents in captivity. The brothers commit suicide and the man is satisfied. Max arrives to pick up the brothers and is devastated to see them dead. The mysterious man later releases the parents to Max and sends a note through them, promising Max that they will meet again.
Between the events of "Brothers" and the next episode, Ben and Gwen go on a week-long vacation with their family. This is never shown but is mentioned.
In "The Legacy Artifact", Ben and his team chase British gangsters Percy Lancaster, Simon Williams and Rick Thomas after they rob the Everstone, an artifact belonging to the Forever Knights. They capture Percy and Simon and learn that the gangsters are ex-Forever Knights and their employer is in fact the Knights' King Philip. Ben's team and the cops are accidentally diverted to the wrong airport where Rick is on the run; elsewhere, Philip murders Rick, but a band of guerrillas blows up the Everstone and kills him. These people are then sniped by a man working for Krill and Wyatt's employer.
In "Authorities", Ben's team and Rozum go on a hunt for a vigilante named "Arrowhead", who is eliminating drug dealers working for a cartel that in fact manufactures the same chemical Krill and Wyatt used to overpower Diamondhead. Arrowhead is in fact Rozum's old friend Dennis Blake, a former detective who lost his job for unknown reasons and has become a freelance crime-fighter. Blake's skills in investigation and combat are extremely powerful, and he helps them take down the cartel and its leader: Ssserpent. They learn from Ben's old short-time enemy that he's a deserter to Krill and Wyatt's employer - the employer has orchestrated events so they all end up in a factory housing an old Null Void projector. Ssserpent is consumed while Ben and his team escape, and Blake is appointed a detective in the BPD 10th precinct.
In "A Monster's Redemption", Ben is seen going on a date with Julie for the first time at Mr. Smoothy's, but Blake calls him on to consult on a murder case in which the victim has zero blood in her body and appears severely aged despite being only 21. Ben visits the morgue with Blake and Rozum and upon examination realizes the killer is none other than Darkstar. Following another murder and later a police dispatch, Ben and the cops confront Darkstar at a road intersection, but he overpowers them, escapes in a car, and overruns a few cops waiting for him in an ambush.
Ben tries to maintain his calmness despite Gwen's anger at him leaving her and Kevin behind - as the cops continue tracing leads on Darkstar's past, Michael Morningstar's psychiatrist, Dr. Richard Wilson, comes into the precinct himself to confess that he keeps Michael's confessions in secrecy as a deal of their trust, though he has one recorded session of Michael's metaphorical explanation to his motives, which he decides to disclose due to his own paranoia. Ben and the others become quite unsettled by this.
Wilson is arrested after bodies in the clinic are found that he hid to protect Michael. Darkstar, however, breaks into the prison he's being held at and starts a riot, with Wilson escaping. Ben, Gwen and Kevin arrive late, but follow a series of footprints and clues that leads them to Darkstar, who is about to commit suicide at the hands of a coerced Wilson. Ben's interruption makes Darkstar livid and he explains his intentions while keeping Ben (as Chromastone), Gwen and Kevin overpowered; Ben is forced to make Darkstar backfire, but the instability causes an implosion that kills him. The cops arrive and Blake gets the body out of the wreckage - Ben and the gang are horrified.
In "The Number Game", Max calls Ben and the gang to the Plumber HQ orbiting Earth following a cyberterrorism strike on the station from the mysterious entity they encountered in "Brothers" and "Authorities". The three bring Ship with them but are shot down, though the rescue team saves them from a crash-landing. Max brings Ben to the Intelligence & Research Center, where the mastermind greets Ben for the first time and the two chat. The hacker reveals to the Plumbers (including visiting Magister Sylax Newell) that a mole is operating within the premises. He sends them three sets of numbers, which Ben, as Brainstorm, deduces to be both GPS coordinates and Plumber ID's, their correspondence achieved simply through the hacker's power. Max sends out teams to the compounds located at the first two coordinates; the third delivers no information due to a seemingly impregnable encryption.
The mission is disastrous - Ben and a few guards discover the body of a member of team 1 in the locker room showers, whose murderer is revealed as team 1's star agent Brian Reed, while team 2 discovers a refrigerated storage unit housing mutilated carcasses of high-profile Plumbers. A ship crashes into the station following the trigger of a mass malfunction among the rescue aircraft; Ben steals Max's Plumber badge among the chaos and uses it to get into an escape pod, which he uses to enter space as Jetray. However, upon his arrival, both compounds explode, severely injuring him and killing the team members.
A hospitalized Ben is visited by Eunice, who is temporarily working as a Plumber doctor, before lead technician Thomas Bridges informs him that Reed wasn't the mole due to inconsistencies between their concrete evidence on the hacker, and Reed's history. The third set of coordinates remains unidentified despite thorough scrutiny, and Gwen and Kevin are sent out to investigate. Ben has secretly placed a tracer on Gwen's helmet, which he later uses to monitor the mission illegally, with equipment provided by Eunice (who Ben promises to take the fall for). Ben's suspicious behavior is later explained by the conclusions he draws following the destruction of a large cloaked warship found at the coordinates: he was cross-referencing earlier observations of Newell with stolen records on the man as well as his behavior during the mission (his suspicion triggered during their lack of friendship and the resulting 'giveaways' in his behavior), thus assuming Newell is indeed their mole. He destroys his equipment and escapes his hospital bed when Max sends Newell to check on him, thinking he is to be assassinated.
As Diamondhead, Ben ambushes Newell in an upper-floor conference room, violently restrains him, and puts him under a ruthless interrogation and incrimination, to which Newell becomes increasingly defensive until Ben warns of the lengths he can take to stop him. Bringing Max in to grant him closure, Ben, ignorant of his grandfather's horror at his misconduct, proves to Newell the legitimacy of his being the hacker's inside man. However, Newell counters with a theory that someone else could have diverted them due to their matching his history; at the same time, Thomas, who has cracked the encryption somehow, murders three technicians to avoid their seeing his name as the source of the data, and is revealed as the mole. Ben is horrified and overcome with guilt at his error, but Thomas calls Max down to the damaged command deck for a meeting.
Ben nevertheless escapes with Gwen and Kevin after his paranoia for Max's safety gets the better of him - this is in fact Thomas' plan, to provide a faulty justification for shooting Max, which he then goes on to do right as Ben arrives. Ben attacks Thomas and nearly kills him until Newell and an army of elites burst in and surround the action, also shooting Ben and reverting him to human form. Thomas, outnumbered, proceeds to deliver a message to everybody: that he, "the patriot", and Newell "the mark", die "in an ironclad will forged in the name of the 'Devil Watcher'", thus divulging the name of his employer. He then follows by shooting Newell with a bullet laced with the "Demon's Blood" chemical Ssserpent was manufacturing; Thomas is then shot by all the elites. The "Devil Watcher" comes on the intercoms and commends Ben and Max for their work, differentiating them from the Plumbers, who he deems lackluster and unfit to continue the ordeal he has put them through. The Watcher counters Ben's skepticism over the payoff for their work by displaying an animation of the numbers he sent them, which produce the photo of some kind of modern living room. Continuing cryptically, the Watcher hints that every event that happened in the last few hours is a potential clue. Ben finally revels in his eagerness at having a formidable adversary, dismissing his negative outlook on the Devil Watcher's ways in favor of continuing forth in his pursuit.
In Heroes of Evolution, Ben is portrayed as a rebellious, laid-back, rude, energetic, easy-going and almost carefree character who is always making jokes and poking fun at others. He now takes his job more seriously and is cold and direct when facing his enemies, showing little fear or respect for criminals. He uses his aliens in a more intimidating manner and exercises his creatures' combat abilities often. Ben is also exceedingly dismissive and carefree towards authority and appears to like to come across as boundless, though this doesn't suppress his generally goodhearted nature. It rather reinforces the humorous and colorful side of them that shines through almost all the time: this trait, however, enhances Ben's departure from character when he turns exceptionally serious.
Ben is shown to be very observant and following his pact formed with the police, he becomes more attentive to clues at crimes and always seeks to gain the upper hand on the enemy - as the show progresses he becomes less and less afraid of fan crowds, though he initially chooses to run in fear. Ben shows little regard to people who think they're better than him and is always rude and confrontational to people he suspects of wrongdoing. His carefree attitude is further shown when he tries to be as friendly as possible while essentially defying his parents - he takes many things for granted but his plans almost always work.
Around Gwen and Kevin, Heroes of Evolution depicts Ben as often not taking them seriously. He regularly informs new friends that Kevin was a criminal, and constantly makes sexual jokes about Gwen and Kevin's dating life, much to their chagrin - Kevin does his best to not embarass himself and keep his cool, but Ben gets off on testing him.
Around Julie, Ben's personality changes to something more affectionate and caring - his sense of humor still remains but he tends not to be very insulting, as he doesn't find Julie to be bothersome. However, he usually doesn't hesitate when called on for work and often uses an excuse to make up for his short-lived time, which Julie seems to slimly tolerate.
Following his meeting with Dennis Blake, Ben's sarcastic attitude still remains, but he has appreciation for what Blake does and takes him seriously following some brief fallout. Anything pertaining to the mastermind behind Krill and Wyatt seems to unsettle Ben as it reminds him of the on-the-spot suicide he witnessed; both he and Max do not mess around when it comes to this man and are both determined to find and stop him.
When Ben is dealing with criminals known to commit horrifying crimes, such as Darkstar, he tends to get more serious and often acts like an adult, going as far as leaving Gwen and Kevin behind to ensure their safety, and running down his thoughts on Darkstar's psychological profile. He is shown, however, to be capable and non-hesitant of violence when necessary, and even acts and speaks from an idealistic standpoint due to the severity of the situation. Ben appears to be a skilled speaker and lectures Darkstar on perspective morals when judging the meaning of Darkstar's justifications to commit crimes.
Ben's darker side, however, takes surprising prominence in his attack on Magister Newell and the prior investigation - his severe injuries put the seriousness of the situation in the forefront - that alongside the fact that the Devil Watcher's mole was still present in the station and had the potential to harm his loved ones (Gwen and Kevin) drives his intensity and determination in closing the case. His intuitive side takes full form when he connects the dots on Newell and concludes that the man is indeed their mole. In his interrogation, however, his antagonistic and brooding nature takes a never-before-seen control, compelling him to do things like using diamond shards (as Diamondhead) to pin Newell's hands into a table following already brutal overpowering of the Magister.
However, Ben's sense of fairness and better reasoning is present in that he allows Max to watch the second half of the interrogation and the exposure of Newell - this is one of the key times at which his dismissal of authorities and lack of fear of consequences takes a hold on the reins. The latter trait was paired with his supportive nature when he promised Eunice that she would receive no blame for supplying him with equipment and records to incriminate Newell. This also paints Ben as one unafraid of sacrifice, a trait already established in Ultimate Alien's "The Ultimate Sacrifice" when he was willing to kill himself to fulfill the intentions of the "escaped aliens". Coming back to his defiance, Ben is aware that the consequences he will face are inevitable, and doesn't mind taking extreme lengths to solve dire situations.
The tables turn when Ben learns that Newell isn't the mole and it's Thomas - here he exhibits severe guilt over the pain he has inadvertently and recklessly inflicted. This also puts the spotlight on his protective side when he becomes deeply paranoid over Max's safety when his grandfather is called down for a one-on-one confrontation with Thomas. He displays defiance yet again when escaping, and proves how protective and loving he is of Max when he viscerally assaults Thomas upon witnessing the man shoot Max. Ben almost kills Thomas before being stopped. Even when surrounded by armed men and told not to move (and stopping to think as well), Ben goes on to move and is shot, being reverted back to human form; he then discloses his dismissal of consequences to the Devil Watcher. From all this it's safe to assume that Ben is invulnerable to authority.
The Devil Watcher
Upon the establishment of Ben and the Devil Watcher's opponency, a characteristic trait of Ben's is brought directly under the limelight: his enthusiasm towards having a formidable adversary. The Devil Watcher's persuasive manner and presentation of the exciting and riveting nature of his "game" attracts Ben immensely, fueling his eagerness to continue with the case despite his recklessness and dark paths he took along the way prior to the discoveries made. Ben's cockiness and adventurous/rebellious nature pair well with the Watcher's lustful menace and justified opportunism, all of which both characters acknowledge with glee and appreciation. Despite the mystery that shrouds the Watcher, Ben does not appear the least bit intimidated by him and feels entertained by the scope and promise that come with the impending battle at hand.
Glimpses of Ben's personal life are frequently shown in Heroes of Evolution and often intercut scenes with him and his friends enjoying spare time - this almost always consists of visiting Mr. Smoothy's. Ben also decides to treat former bullies Cash and J.T. like friends and invites them and other friends of his for soccer occasionally.
Ben's time at home is relatively unchanged from Alien Force and Ultimate Alien; he takes a keen interest in the Sumo Slammers franchise and often drifts into laziness at home - his pact with the police seems to extend into his unwarranted taking of liberties in the department, though it doesn't seem to irritate Captain Rozum or anyone else since he is a great help to the police. Rozum even goes as far as informing Ben of details in police casefiles. Ben also has a similar association with Blake, who regularly calls him for leads and consultations. Ben is also shown to read comics at home when his TV is unavailable, such as when the power goes out during a rainstorm in the sixth episode.
Ben's relationship with his parents is very open-ended like they encourage in Alien Force - he deeply cares for them but doesn't hesitate to lie about certain things pertaining to his life as a hero - he's quite goofy around home but his parents seem to tolerate him. Despite all his rude humor and hint of narcissism, Ben is still light at heart and fully capable of showing utmost respect to his loved ones.
- As Natalie Tennyson has said in the canon, Ben's table manners are relatively poor - this is shown in "Authorities" - though he was a bit uncomfortable while in the middle of a police case, he still behaved awkwardly and constantly needed to excuse himself. He'd also make jokes back to certain people at times and discomfort Gwen and Kevin.
- Ben seems to treat his car recklessly at times - in "PIlot - Part 2", he transformed into Humungousaur while still in the car, creating a large cloud of smoke to intimidate incoming soldiers - the car, however, had its left side smashed open and Kevin was forced to rebuild it for him - Ben relied on racing laps around Mr. Smoothy's to test-drive it, and this irritated Gwen and made her go home. He also later took a second car accident lightly, and while his car was still fully functional, his talk with Kevin about it was merely a conversation and not a heated argument.
- Ben's treatment of excited fans relies more on consolation rather than retreating, though an imminent situation that will prove deeply uncomfortable causes him to give up and run off - this is shown in "The Legacy Artifact" when he is afraid that an excited man's daughter (who's obsessed with him) will act on such impulses.
- Ben still enjoys outlandish flavors of Smoothies - while he shows mercy to newcomers and doesn't prank them with the kind of drinks he has, he still casually informs them of his unique taste and refers to their flavor list as "ingredients from all your local fast food shops".
- Ben's love for soccer comes with a more insistent edge in this series - he encourages his friends to play but Gwen and Kevin prefer basketball, much to his frustration.
- Ben admits to using aliens to scare off paparrazzi - he is also implied to have used his watch to play sports he doesn't like or is not good at, such as basketball.
- Ben is shown to break character when dealing with something that disturbs him deeply, such as Darkstar - he turns into somewhat of an idealist during his final encounter and demonstrates his speaking skills when lecturing Darkstar on morals.
- Ben appears to have a reasonable understanding of criminal psychology - when talking to the police at the morgue, he acknowledged his perception to Darkstar's sadistic and bloodthirsty nature, yet when informed of Darkstar's intentions to fix himself and his description of his murderous cycle, Ben is able to take this in and empathize with it despite idealistically judging the overall justification.
- Ben is proven to be a keen detective who can draw reasonable conclusions through substantial proof - while Sylax Newell laments his understanding of the human psyche as "appalling", he later admits that Ben's observations on his behavior are relatively legitemate pieces of evidence towards his potential role as a traitor. When working with concrete evidence, Ben is equally as perceptive. He admits to enjoying working with the police.