Kevin Levin (TNO)

Kevin Ethan Levin is an Osmosian and a member of Ben's team. When Kevin first appeared in the original series, he quickly became one of Ben's most notable enemies. However, he reformed in Alien Force, and became one of the main characters until his departure, along with Gwen in The More Things Change: Part 1.

Appearance
In the original series, Kevin is a thin and scrawny boy with shoulder-length black hair, pale skin and dark brown eyes with black-discolored marks around them (a sign that an Osmosian has recently absorbed energy). He wore a torn black T-shirt, black studded arm bands, brown cargo pants, black knee-length shoes, and a padlock necklace which is a spoil from his first crime: stealing a bike and using it to run away to New York. After absorbing an Omnitrix feedback, Kevin was able to transform into exact copies of all of the unlocked aliens, missing an Omnitrix symbol. After the energy overwhelms Kevin, he mutated into Kevin 11, a random mixture of body parts from the 10 said aliens which completely destroyed his clothes, except for his cargo pants.

In Alien Force, Kevin grew into a tall and muscular young man. His eyes now lack the black marks (as his body fully recovered from and stopped absorbing energy). His normal attire is a tight black T-shirt over a grey long sleeve shirt, blue pants, and black combat shoes. His hair, although still long, is styled into a choppy mullet. Occasionally, he is seen wearing a short sleeved light blue oil stained mechanic's jacket over a white muscular shirt, blue pants, and his black combat shoes. After he goes through a second mutation, an unbalanced mixture of various matters, the transformation completely destroys his clothes, except his briefs. As a result, Kevin had to wear an in public to appear human. In his second mutation he looked like a mixture of solid materials such as stone, wood, Taydenite, and metal. During Kevin's time as Ultimate Kevin, his appearance is again an unbalanced mixture of various aliens that were currently accessible to Ben through his Ultimatrix.

In Omniverse, Kevin wears the same black shirt but the sleeves and collar are roughly cut, the sleeves on his long sleeved grey shirt are slightly torn and he wears blue wholesters. His hair is longer and straighter. His pants have a small tear below the left knee. He also wears a padlock necklace similar to the one he wore when he was 11 but marked with an "11". He also sports black discolored marks around his eyes, making him appear tired; these marks bear similarity to when he was 11 and still absorbing energy.

Later in the series, Kevin grows a few chin whiskers and his grey shirt gains stripes. In Weapon XI: Part 2, Kevin gets the same cross-shaped scar to his chin that future Kevin has.

In The New Omniverse, Kevin wears the same black shirt but the sleeves and collar are roughly cut, the sleeves on his long sleeved grey shirt are slightly torn. His hair is longer and straighter. He wears the same pants from Ultimate Alien/Alien Force

Personality
Due to his complicated childhood and abilities, as a child, Kevin exhibited sociopathic tendencies, such as attempting to derail a money train, even though it'd kill countless passengers on another train. Kevin had an extremely negative outlook on life because of his countless hardships and struggles, feeling insecure about himself as well as having an incredibly low self-esteem. He had a deep-rooted hatred for other people and society in general. He was paranoid to the point of considering everyone to be his enemy because, as he put it, "Nobody's innocent! They just haven't had the chance to make fun of me yet!".

Kevin's outlook began to change when he met Kwarrel, a fellow prisoner in the Null Void. Becoming somewhat of a mentor and father-figure to him, Kwarrel helped greatly improve Kevin's personality. In Alien Force, despite Kevin having become a con artist and an arms broker, he was more stable and somewhat mature. As time went on and Kevin was accepted by Ben and Gwen, who were once his most hated enemies, his personality and psyche improved greatly to the point that he became a trustworthy and reliable ally. He once told Ben in Perplexahedron that he was grateful to them for changing his life. Verdona stated that Kevin's current personality is similar to a younger Max's.

While changing for the better, Kevin still sometimes shows a delinquent side, as seen in Kevin's Big Score, where he attempts to sell the Rust Bucket to Vulkanus for alien technology, albeit technology he intended to give to Ben, and conspires with Argit to sell weapons to both sides of a warring race in Simple. Despite this side of Kevin, Ben and especially Gwen still greatly trust him.

Though Kevin can still be cynical and insensitive, he is a good person at heart and generally doesn't like innocent people getting hurt. Though he is rarely open about it, also has a sensitive side, as seen in Con of Rath when Jarett ate the Tiffin - the scene was so shocking to him that he fainted, despite the fact that he is supposed to be the "tough guy" of the group.

Despite having adopted a more positive outlook on life since meeting Kwarrel and making friends with Ben and Gwen, Kevin still suffers some insecurities, which are most evident when he is mutated. The second time he mutated, he was visibly disgusted with himself and fluctuated between bouts of uncontrollable aggression and severe depression that jeopardized his relationships, especially with Gwen. As Ultimate Kevin, he voiced his frustration against Ben for being a famous superhero and him "still" being a freak.

While he cares for innocent people, he is willing to end life, as he voiced to kill any villains that went after his family or the Tennyson's. He also was willing to let Ragnarok die to avenge his father. Kevin even advised Ben to kill Victor Validus in order to kill the Nanochip Queen inside him.

Kevin is extremely protective of his car and becomes very upset whenever it gets damaged, which happens on a fairly regular basis.

Background
Kevin Levin is born to an unknown father and Mrs. Levin. Sometime after his father's death, Harvey Hackett came into their lives. Harvey fell in love with Mrs. Levin and married her, becoming Kevin's stepfather; according to Harvey, Kevin was only 4 years old at the time. Kevin wasn't fond of Harvey at all, especially since he saw him as a replacement for his real father as well as an obstacle for Mrs. Levin's love. Harvey tried to be a good father to Kevin, he accepted and raised Kevin as his own, but he feared Kevin because of his Osmosian powers, which only worsened their relationship. When Kevin was 11, Kevin managed to absorb energy and demolished their house, according to Harvey. This, coupled with the mental instability from absorbing the energy and his dislike of Harvey, instilled in him the delusion that Harvey convinced Mrs. Levin to kick him out in the street (Harvey admitted that he ran Kevin out of the 'house' because he destroyed it). He stole a bike, wearing the padlock around his neck, ran away and made his way to New York, where he made his home in an abandoned subway.

Five years prior to Omniverse
Kevin is found by the Rooters, who did experiments with his Osmosian powers on Alan Albright, Helen Wheels, Manny Armstrong and Pierce Wheels, turning them into the Amalgam Kids, making them do nasty things. After that, Kevin fled, only with Servantis controlling his memories, convincing him that he had "alien blood".

Eventually, Kevin and the Amalgam Kids confronted Ben, Gwen, and Max and Kevin fired a blast at Ben. Ben manages to avoid the shot and pins down Kevin using Eye Guy. However, Kevin did this to get Ben to come closer and touches the Omnitrix causing Kevin to mutate again. Kevin, like Ben stated, starts to go insane again and even attacks his allies the Amalgam Kids. Kevin was eventually stopped by Argit who used his quills. Kevin and the Amalgam Kids were sent back to the Null Void but an enraged Servantis wiped out their memories and sent them away. Servantis then abandoned the plan to destroy Ben after Ben stopped wearing the Omnitrix and Kevin escaped from the Null Void at some point.

Two years after breaking away from Servantis, Kevin began work on his car, not satisfied with a simple standard model he began outfitting it with Alien Tech, and to this end traveled to Khoros to acquire a Tetramand engine block for it. Since the tech couldn't be given to an outsider he wooed the then teenage Princess Looma Red Wind and successfully defeated her combat earning the right to marry her in three years thereby making him a part of the family and was given the engine as a gift.

Powers and Abilities
Originally, Kevin's powers were believed to be of an unexplained mutation, then alien heritage but later explained to be of a unique genetic component.

Kevin has the ability to absorb the energy and matter of anything (excluding certain materials as seen in Greetings from Techadon) through his body at will and utilize it in various ways.

Energy Absorption
After absorbing energy, Kevin can channel energy through his hands to manipulate technology, discharge it as an energy blast or use it to speed up cellular regeneration to increase his strength or recover from injuries at an accelerated rate. However, the energy will dissipate over time or through excessive use, so he is required to recharge.

However, if Kevin absorbs energy, the energy will cause Kevin to become mentally unstable. Storing energy for long periods of time will worsen his instability. This mainly occurs in Osmosians who absorb energy very often but cannot control it due to inexperience and lack of skill. Energy absorption can sometimes easily turn into an addiction.

When Kevin has recently absorbed energy, he develops black marks around his eyes. This is a side effect of absorbing energy.

Power Absorption
Similar to his ability to absorb energy, by absorbing the DNA, metabolism, and life force of other life forms, Kevin can use it as nourishment to sustain his health and strength. Absorbing all of someone's energy will kill them. Kevin can use the energy to acquire the creature's powers and undergoes mutation to accommodate the absorbed abilities.

Despite complete access to any of these absorbed abilities at anytime, they aren't as strong as their pure forms, as noticed by Diamondhead who estimated that they are only about 1/10 their full power, as seen when he was able to catch and crush Kevin 11's crystals with his bare hands while the others shattered upon hitting him. This was proven correct by Aggregor. This is the reason why Aggregor first turned P'andor, Andreas, Bivalvan, Ra'ad and Galapagus into pure energy before he could absorb their powers and abilities so he could attain their full powers and abilities. He also stated that when Osmosians absorb the life force of other beings, the new powers can only be used temporarily unless they were to drain all of that life form's energy.

This ability can also be used to combine the DNA of two beings, which is what Servantis used Kevin for. As seen in The Rooters of All Evil, Kevin was able to absorb some of Servantis' energy that brought out some past memories. Kevin was able to carry the energy around on his hand and used it on Argit and Alan Albright to bring up their past involvement with the Rooters. Kevin then used this energy to his advantage as he was able to permanently lock out Servantis from the Amalgam Kids' minds.

Matter Absorption
Kevin can absorb solid materials, coating himself in the substance which allows him to take on its properties. He will proportionally increase in physical strength and durability to whatever he absorbed.

In Plumbers' Helpers, Kevin was able to absorb multiple materials at once. In the same episode, he also displayed the ability to apply to other people a coating of whatever material he has absorbed at the time, temporarily.

Depending on the amount of the absorbed material Kevin has available, and how he distributes it, Kevin can either coat his body, or part of it, in the material as a second skin like armor, as revealed in All That Glitters, or completely convert his body, or part of it, into a living version of the material. The amount that Kevin requires depends on the density of the material.

This ability has once been used productively when Kevin was forced to synthesize a coating of Taydenite, thus incapacitating him.

Matter Manipulation
In Alien Force, following his second mutation which causes him to lose the ability to revert to his human form, he gradually begins learning how to use his absorbed matter in various new manners. He is able to use high levels of strength and durability as well as regenerative and shape-shifting abilities. After returning to normal, he retained his newfound powers due to him now having knowledge of being able to doing so.

In Too Hot to Handle, Kevin's abilities have shown to have developed more, allowing him to repair objects of the current material he has absorbed either by turning it into a liquid form or releasing a liquid version of whatever material he has absorbed. He can partially merge with the actual matter and manipulate the substance's form. Both abilities were used when he repaired the rock ceiling of a mine, fused the seal of P'andor's suit, morphed it around P'andor, and fused the arms together as makeshift handcuffs. In The Creature from Beyond, he used the metal he absorbed to create a helmet for Gwen to prevent the Lucubra from controlling her.

Kevin can easily pick locks, using his powers to absorb the material of the lock, then form his finger into a key.

Kevin can also absorb liquids, and when he does he gains the properties of that liquid. If Kevin absorbs mud, objects will pass through him without causing physical damage. He can even absorb bubblegum.

Other Skills and Abilities
Even without his absorption powers, Kevin is shown to be stronger than an average human. As Ben noticed in Trade-Off, even the powerless Kevin was still a fairly proficient fighter and a useful asset to the team. While not to the same extent as aliens like Tetramands, Kevin is capable of lifting/throwing the combined weight of several people with little strain. He is also capable of resisting impacts and blunt force trauma that would severely injure an ordinary person with moderate discomfort.

Kevin has some noticeable skill in martial arts which he gained during his years as a runaway, a prisoner in Incarcecon, an alien tech dealer, and a member of the Plumbers. With this combat skills, he has proven on several occasions to be a highly formidable fighter, having held his own against and defeated opponents such as the Megacruiser robots, Technorg, and even Vilgx in a one-on-one fight.

Despite lacking a proper normal education, Kevin possesses a vast scientific and technological knowledge of alien paraphernalia. In Deep, Ben and Kevin argue that they both cannot use their powers while being in their Plumber suits. So Kevin made some alterations to the suits, equipping them with propelling units and shock pulses that allow them to attack with electric shocks. Kevin also has great analytical and deductive skills, having been able to determine and find out specifically what happened in a battle between Aggregor and the Plumbers several hours after the battle, greatly impressing his friends and even gaining a compliment from Max that he either could be an expert police officer or a wanted criminal. Kevin has good motor skills, being able to race and chase in his car and the Rust Bucket 3.

He is also great at mechanics and engineering. He is shown to repair his car for the numerous damage it took during the course of the series. He also modified his car, setting alien tech for beneficial gears. On top of that he built the DX Mark 10, a car that he reluctantly gave to Ben as his sixteenth birthday present. Kevin is also shown to be very good with animals, even without trying. In Deep, a Blowfish became strongly attached to Kevin. Later, Khyber's dog, despite being well-trained and loyal to Khyber, ultimately chose to join Kevin, even saving Kevin from being crushed.

Trivia

 * In Omniverse, Kevin lives in the same area as Gwen's college rather than Bellwood.
 * Kevin is keeping the Taydenite car, but will rebuild his old car and will just use the Taydenite for when he needs some money. This was shown true in Charm School.
 * A running gag is Kevin becoming distraught every time his car gets damaged or destroyed during combat or miscellaneous events. The Rust Bucket 3 has also become a part of this running gag.
 * In The Widening Gyre, it is indirectly stated by Kevin, that he watched "Captain Planet" and "The X-Files" when he was younger.
 * According to Waybig101, Kevin will have another mutation in Ben 10: The New Omniverse.