Gwen Tennyson (Earth-68)

This version of Gwen Tennyson is the one that appears on Earth-68, the universe owned by Dioga beta. The series Kevin appears in are the John Smith 10 franchise, John Smith 10: Final Fantasy, and Ryder 10.

Dimension 1 (John Smith 10)
In John Smith 10, her powers are the same as the canon series. She is an Anodite, an energy being made of mana. She utilizes these powers to fight, as well as her extensive hand-to-hand combat training. She is extremely intelligent, able to figure out complex problems quickly. However, when put in situations of pressure, such as difficult decision making, she becomes nervous and unsure of herself.

History
Gwen's family moved back to Bellwood, as it was her father's hometown. Upon enrolling in school, she meets John Smith, a boy with the Omnitrix. They become quick friends, when they are attacked by a Techadon Robot. Gwen reveals her magic powers to John to fight it off, before he reveals his powers, the two defeating the robot. John then invites Gwen to join his superhero team, with Eddy, also asking if she'd go to the school dance with Eddy. Despite feeling tricked, she agrees. At the dance, the group is attacked by another techadon robot, and they defeat it. Gwen helps stop the Techadon robots, as well as help rescue John from the Forever Knights.

When a large number of bounty hunters come after John, he gets Gwen to help drive them off. However, they are both defeated by Rob Lucci, John being taken away. Gwen is left behind, and goes over to one of the bounty hunters, Kevin Levin, demanding his help. Kevin refuses at first, but eventually agrees. The two go up onto Vilgax's ship, and fight him while rescuing John. They eventually escape, and they are stranded on Flors Verdance. Kevin fixes the ship after being rescued, and they escape.

She is told by Kevin and Professor Paradox that her magic powers come from alien descent, which she denies. However, after meeting her grandmother Verdona, she learns about her heritage. She is given the chance to go to Anodyne to master her powers, which would take about 75 years. She goes into a panic on trying to decide, until Kevin says that he'd miss her. She decides to decline the offer, when the group is forced to fight Verdona. She convinces Verdona to let her be a kid, and she does, leaving.

When Kevin lost his Plumber badge, she tried to make him feel better. She learned about his dad's history as a Plumber. When Eddy didn't appear for a gathering, she was the one who was worried and got the others to go look for him. They discovered the Highbreed's plans to use him to build a jump gate, and rescued him. The heroes later return to disable the jump gate, but are too late, as it opens. She, John and Kevin go up to the control tower to stop the invasion. However, when pushed to the limit, she enters her full anodite state to defeat a Highbreed commander. She almost obliterates the Highbreed army, but Kevin calms her down, her reverting.

When the group first encounters Hex, she instantly recognizes him, saying that he inspired her to study magic. It is later revealed that when John and Hex went back in time, John brought Gwen's spellbook, and found her in Salem, Massachusetts. She gains the book, as John fights Hex. After they leave, Gwen begins her study in magic.

When the group goes to Plumber academy, she's the one who was suspicious of all the strange events going on. They eventually found a conspiracy to destroy the base with Basilisks. They manage to stop the threat. When Kevin seems to go back to his criminal ways, she is the one to critique him and tell him it was wrong. He eventually fixes his mistake.

When Rob Lucci leads a group to get John, she helps Kevin fight Dr. Vicktor and Sonogram while John goes to save Julie. They arrives to fight Lucci as Wildmutt. She witnesses John's death, and in a blind rage, kills P'andor, Vicktor and Sonogram. She tries to comfort Julie afterwards, and gains an Omnitrix to chase Julie through time with Clockwork. She unwillingly gives Albedo the Omnitrix, as they find Julie and take her back. She later uses a time travel spell to go back in time to prevent John from being killed. This created an alternate time line, where the John is a hardened soul. When she takes him back to the main timeline, he is unable to adapt to the new time, and takes the place of the main John, dying.

After John breaks up with Julie, she is greatly upset with him, especially when he shows affection to Eunice. When Gwen meets her cousin Sunny, who is also an anodite, tension occurs almost instantly, causing a battle between the two of them. When Kevin goes on a Vendetta against Ragnarok, she tries to help him get over it, but is sent back down to Earth so she can't do anything.

In the Negative 10 incident, she initially fights the Vreedle Brothers. She later confronts Dr. Animo and Charmcaster, marking one of her few personal incidents against Charmcaster. She drives them off, and is surprised to learn of Lucci having the Ultimatrix. She goes with Kevin to fight the Negative 10, but is captured and defeated. She and Kevin are rescued by John.

In previous incidents with the Forever Knights, she befriended one named Winston. She is called upon to fight a creature known as the Lucubra, calling in John and Kevin to help. The Lucubra leeches into her mind, taking control. She is able to resist thanks to gaining a metal helmet, as she seals the Lucubra away.

She is initially against helping Charmcaster going to Ledgerdomain, but does so anyway. She gains a power-up in the realm of magic, but is still not a match against Adwaita.

During the incident with Techadon Weapon Master Number 13, Gwen gains her own piece of the Omnitrix. She uses it considerably less than Kevin does, who gets his own piece, preferring using her own powers over the Omnitrix. However, she does use it on occasion. She gets an episode featuring her average day, with massive school commitments, subbing for teachers and still having to help John. When Julie disappears, she becomes concerned for John's well being, and promises to help in anyway possible.

Diagon uses his connection to Gwen from the Lucubra in an attempt to control her, but is saved when Kevin gives her a metal helmet. They call in all their allies to help fight Diagon. Gwen helps John and Kevin fight Winston, who currently has the fourth Omnitrix piece. Afterwards, she helps fight the Lucubra, sealing them away.

Galactic Battle
Her role in the early part of this series is limited to backup. She assists fighting Aggregor, and has to fight Hex during that time. She is the one who suggests to go save Charmcaster from Ledgerdomain, though her views change when Charmcaster kills them. They're revived, but her trust is broken. She was troubled by John's reaction to Charmcaster's death.

She is called upon to save John, who had been captured by the Separatists. This entangles her and the others into the Clone Wars. Gwen becomes a General, and leads his own army. Her Plumber units are Michael Morningstar and Red Ninja. Gwen is extremely nervous about leading her own forces, questioning her ability to lead. Michael attempts to comfort her and gain her affection, though she refuses him. Red Ninja watches over her intently, working to protect her. When the Separatists gain a Lucubra, she gives command to Michael do to her losing control of herself, which resulted in multiple casualties. She regains control, and gains confidence in defeating them.

When Gwen's forces join up with John's and Kevin's, they are ambushed by Sevenseven and his battle droid army. A bomb that goes off desolates the field. Magister Prior Milhil arrests Kevin and Lucy Mann for treason. Gwen and John learn it was really Michael that betrayed them, and after failing to appeal to the Senate, left the Plumbers to save them.

Afterwards, when both John and Kevin get mutated, she leads the group of girls, being Lucy, Eunice and Ahsoka Tano to try to fight the Separatists. They eventually find out that Michael was a double agent working for the Chancellor, who had instigated the whole war. They track the Separatist leaders to a planet, where they attempt to capture them. However, the battle between Ultimate Kevin, Ultimate John and Ultimate Michael prevents this from occurring, Michael killing the Separatist leaders. John reverts Kevin and Michael to normal, them saving Kevin as Michael falls to his death. After Wes helps the group clear their names and reinstated, Kevin and Gwen go to Earth to recuperate. They are attacked by Metal John, and defeated.

Phantom Watch
Before the events of Phantom Watch, Gwen and Kevin encounter Phantom, an alternate dimension John who had lost his left arm. They try to find a way to regrow it, when they meet with Sunder, who had recently had his arm regrown. He said that Azmuth did it, so they take Phantom to Azmuth. Azmuth turns them down, however, but Phantom stays behind to convince him otherwise.

After Phantom teams up withAlbedo, and takes over the Earth, they use Animo's de-evolution bomb to turn everyone into zombies. Gwen becomes one of Phantom's primary followers, heavily under his influence. In the final round of the War Games, she fights Charmcaster, who was grieving over Hex's death. Gwen uses this to her advantage to discourage Charmcaster. John snaps Charmcaster out of her trance, and after a close match, Charmcaster loses to Gwen. Gwen goes to kill her, but John stops her. After the War Game ends, Gwen and Darkstar try to attack the heroes, but are stopped by John.

Gwen re-appears to fight Charmcaster's group in Phantom's castle. However, Charmcaster defeats Gwen this time, despite the fact that Charmcaster and her team are captured by Gwen's forces. She joins all the zombified friends to fight John, and is healed by an evolution bomb. She instantly rejoins John, assisting in fight Albedo and Vilgax. She fights on the ground with Kevin to fight the Bioids.

Ancient Times
Gwen's role in this series diminishes. She goes with John and Kevin to go after Dr. Eggman. When John was separated from them, they spent several episodes off screen looking for him. She teams up with Kevin to chase Rouge, then later with Rouge to flood a security room.

She assists in helping to save Greece, after Vilgax takes over Olympus.

Kingdom Hearts
She appears briefly in the first episode, talking with John. She tells him to talk to Julie, before he's taken away.

Omniverse
She has not appeared yet, though she will in the future.

Dimension 10-X
In John Smith 10: Distant Worlds, Gwen has an alternate dimension persona named Diana. She was the Queen of the Chess Pieces, influenced by the Orb of Caldia. She serves as the instigator of the entire MÄR Heaven arc, but only appears once.

Dimension 777 (John Smith 10: Final Fantasy)
Gwen's story in this Final Fantasy parody greatly varies from her regular canon appearance. She appears as a "slave" of Zombozo, being beaten and starved by him. She is rescued by John, but the psychological trauma she suffered persisted throughout most of the first season. She was quiet and reserved, seeing John as her new "master." It took long amounts of work for John to help her adapt to a normal life. She eventually does, her confidence and abilities growing in the process.

Due to seeing John as her "savior," she develops a bond and possible crush on John. She doesn't like to be separated from him, and feels safest with him.

She still has mana powers, however they are weak and underdeveloped due to being punished if she used them. However, the alien form Will-o-Wisp lives in her, drastically increasing her powers.

Dimension 2 (Ryder 10)
Gwen has not yet appeared in Ryder 10. However, she shall appear in the series in the future. She will serve more as a villain instead of a hero.

Dimension 720
This is an alternate future Gwen that appears in Little Red Headed Girl. She was killed by the Galvanic Techadon.

Trivia

 * Her confidence problems stem from the canon episode What are Little Girls Made Of?
 * Gwen's story in Final Fantasy inspired the warning at the beginning, due to talking about the deep and graphic issue of slavery and abuse.
 * Despite having many episodes focusing on her, most of her backstory is unknown, and her character less developed than Kevin in the John Smith 10 series.