Berserk Button: Trying to hurt any innocent people or anyone close to him. Then he will get serious and beat the crap out of you. And God helps you if you actually suceeded in harming someone seriously...
The Unchosen One: By Azmuth until the finale of Ultimate Alien, where he finally admits Ben is worthy and gives him the final version of the Omnitrix.
Chronic Hero Syndrome: one of his most defining traits from the beginning of the show; when he got the Omnitrix, the very first thing Ben thought about was to see if he could use it to actually help people with it.
Comes Great Responsibility: played with; he is willing to use them for good purpose and will usually be careful about that, but he has most of the times few problem with using them for petty reasons, especially as a kid.
Leeroy Jenkins: zig-zagged; he tends to act like this sometimes, but other times he will actually display some sense of strategy and cunning, especially in the Alien Force/Ultimate Alien era.
Future Me Scares Me: Though initially in awe of Ben 10,000, he later calls him on being a Jerkass. Ben 10,000, meanwhile, has a case of I Hate Past Me. Although that isn't the REAL Ben 10,000. Whether Ben would've ended up being that version of Ben 10,000 had he not traveled to the future in the first place is unclear.
Hidden Depths: In Ultimate Alien, it is suggested that the whole Idiot Hero act and constant one-liners in this series were a coping mechanism so he could deal with having to make life-and-death decisions on a more or less daily basis.
Characterization Marches On: In Alien Force's first two seasons, he was a very different character from what he was before; in season 3, the writers took the liberty of making him more like his younger, immature self...a little too much like his younger self. Fortunately, by Ultimate Alien they moderate his competence and silliness as opposed to focusing on one or the other.
The Charmer: He has several girls that like him and doesn't mind that at all, but he doesn't actively pursue women though like a Casanova does.
The Messiah: Less so after Alien Force's first arc, but still shows some signs.
Midseason Upgrade: Ben 10,000 gives Ben all of his locked aliens that he'd used up to that point along with some new ones in the middle of season 2. He also brought back Swampfire and Waybig after the two were eroded into dust by Eon.
Older and Wiser: Not much wiser, mind you. He's still a kid at heart.
This is subverted when he was at Plumber's Academy. He acts dumb but in the end got a 95 out of 100 because just because he acted dumb, didn't mean he wasn't paying attention.
Pride: Deconstructed. By the first season finale, he outright states that he's grown tired of what comes along with his fame. In fact, his constant pestering due to fame and time it took up was revealed to be a major factor for his relationship with Julie taking a big hit.
Hyper Competent Sidekick: Gwen was a prodigy who could basically instantly master anything, be it athletics, academics, and even the Omnitrix in a "What-If" episode, in which she's instantly better at using it than Ben ever was.
One-Winged Angel: Being half Anodite, Gwen is able to transform into a much more powerful Anodite form, but it's apparently very risky as the first time she nearly goes Drunk with Power.
Heel Face Revolving Door: Went from neutral to evil shortly before his debut, turned good at the start of Alien Force, turned evil again 3/4 through Ultimate Alien's first season, then reverted back to good in the Season Finale.
The Other Darrin: As a kid, he had two voices: one in his first appearance, then another in his future appearances.
Slasher Smile: Does this a lot as Kevin 11 in Ben 10 and Ultimate Alien.
Wicked Stepfather: Kevin implied to have had one in his youth. It turns out to be a completely false viewpoint of Kevin when he's insane; his stepfather is actually a good man.
With Great Power Comes Great Insanity: Used in Ultimate Alien to finally rectify his extreme change in character. He falls off the proverbial wagon again five episodes later.
Original Series
All Your Powers Combined: He at first had Ben's ability to transform, but after getting frustrated with Ben just giving up on him, he turns into an amalgamation of the original ten aliens.
Ax Crazy: As Grandpa Max puts it, "That kid's rowboat is missing a few paddles!"
Evil Counterpart: Was basically Ben but without any of his morals or standards.
Family Unfriendly Death: Gives one to Slix Vigma by impaling him with his Diamondhead arm...and if Ben hadn't gone Cannonbolt, he would have been next.
Freudian Excuse: Everyone treated him like a freak and a monster because of his powers, so the unstable kid basically decided to do his damnedest to prove everyone right.
"Nobody's innocent...they just haven't got the chance to make fun of me yet!"
Book Dumb: Plays at this, but is in fact not. Gwen notes that he's good at math and a top-notch engineer, as well as having a knowledge of history. It helps that he literally hasn't gone to school since the age of 11, and most of what he knows he learned on the streets by doing rather than from books by studying.
Easily Forgiven: Only recently has any mention been made of his prior characterization ("criminally insane"). However, there were signs of Ben questioning his trust in the first few episodes until he trusted him entirely. Although given that he antagonized Ben for a whole season, you think it would've taken just as long to have Ben forgive him, not just a fraction of a season.
Like much of the Author's Saving Throw involved with Kevin in Ultimate Alien, this is attempted to be explained with a rather convoluted explanation about Ben's subconsciousness and involving Paradox.
He gets hit with this trope AGAIN in the Ultimate Alien Season One finale. Energy-induced insanity or not, he literally is forgiven for what the crap pulled after one simply "Sorry, man." See Karma Houdini below.
Extra Ore Dinary/Chrome Champion: Capable of turning his body into various metals and/or solid materials that he touches, due to being part Osmosian.
Freak Out: When he's transformed again in Alien Force after he and Ben (unsuccessfully) attempted to hack the Omnitrix. And once more in Ultimate Alien after absorbing the aliens in the Ultimatrix.
Heroic Willpower: A flashback in Ultimate Alien reveals he had to concentrate to get back to normal from his transformation in the original series.
Heroic Sacrifice: Non-fatal example. He saves the universe and defeats Aggregor, but at the cost of his sanity.
Karma Houdini: While no-one wanted to see him get killed since he wasn't in total control of his action, the lack of any sort of permanent consequence for him after his vicious crimes while insane (major collateral damage, attempted murder, possible offscreen murder, etc.) is a little jarring.
Not to mention driven further home how everyone seemlessly forgives him after he makes a wisecrack the moment he's reverted back to normal.
Midseason Upgrade: Gets shapeshifting powers in The Vengeance Of Vilgax which make him stronger, which he retains even after being restored to human form. Made a plot point in that if he hadn't got them, they'd have been unable to save the world from Hex. This really helps increase his usefulness to the team.
Reformed Criminal: Mostly. By his own admission, he's not entirely trustworthy — and a lot of the tech he has in the back of his ride is stolen. Though in his defense, most of the ones he stole from were enemies they were fighting.
The Resenter: When he goes insane again after absorbing the Ultimatrix's power Kevin reveals a great deal of resentment towards Ben. Ben always beat him when they were kids, Ben becomes a world famous superhero while Kevin gets turned into a monster, Ben gets a happy homelife...it's always Ben who gets everything. It's not really made clear how much of this is just the energy-driven insanity speaking and how much of it is real.
Roaring Rampage of Revenge: After being driven insane in Ultimate Alien he decides to go on one of these whenever he's not absorbing other peoples powers.
The Worf Effect: He's usually always the one who gets his ass kicked the most in battle.
Maxwell "Grandpa Max" Tennyson
Adorkable: Back when he first met Verdona, he managed to hit this trope while still being badass. The early 1960s setting- so early that one would think it to be fifties if not for the Kennedy reference- definitely helped.
Clingy MacGuffin: Though by the last season of Alien Force this is no longer true, as Ben knows exactly how to remove the thing whenever he wants. He just doesn't want to.
Dee Bradley Baker: Unless stated otherwise, this guy voices all the aliens introduced after Alien Force and replaces most of the alien voices from the original series.
He's probably breathing a sigh of relief since he's not gonna have to massively overwork himself/ run out of different voices in Omniverse, considering Bumper Robinson is going to voice some of the aliens along with other unannounced voice actors voicing others.
Self-Destruct Mechanism: Depending on how long it's charged, it could blow a person's arm off (that is, unless they're Made of Iron) or destroy the whole damn universe.
Sealed Good in a Can: Ben had the alien locked in the Ultimatrix so that it can only be activated for emergencies, and so Albedo couldn't access it were he ever to get his hands on a Codon reciever again.
Voice of the Legion: When he does speak, it's Bellicus, Serena, and Ben in unison.
Fauxshadow: One episode has him going out of Ben's control, and Gwen believes that he's following in the footsteps of Ghostfreak, since they're both ghost-like aliens. But actually, no, BC was just getting ready to be a mommy/daddy/whatever.
Glass Cannon: Unless he's using his intangibility.
Me's a Crowd: Unlike Ditto, however, the duplicates are not constantly synced to each other, so it is possible for each one to transform into different forms separately, as seen in episode 2 of the newest series. Unfortunately, Ultimate Echo Echo is incapable of this.
Robo Speak: Sounding like a speech synthesizer as Echo Echo, but loses any inflection and goes straight into Creepy Monotone as Ultimate Echo Echo.
Vocal Evolution: Richard McGonagle uses a deep growling voice early on in season 1 of the original series. By season 2, he uses the higher gargling tone Fourarms is known for.
Ghostfreak (OS-04)
And I Must Scream: Unlike other species sampled for the Omnitrix, even the smallest sample of DNA contains an Ectonurite's consciousness. A copy of Zs'Skayr's consciousness was subsequently trapped inside the Omnitrix and fully aware the entire time.
This Looks Like a Job for Aquaman: His usefulness is limited in battle, but finds practical uses in other areas, such as saving a planet from being split apart.
Voluntary Shape Shifting: To a point. He can flow through any opening his little saucer can get through.
Weaksauce Weakness: Take away his saucer, and he's immobilized. Ben uses this to get the Omnitrix back from Vilgax on Primus.
Helium Speech: For Ultimate Alien, to go with his microscopic stature.
Hey, It's That Voice!: In "Alien Swarm", Nanomech was voiced by Alex Winter (Yes, that Alex Winter), who also directed both that and "Race Against Time".
Hive Mind: In Alien Swarm, turning into Nanomech made him hear the voice of the Queen. Luckily, he resisted.
One of the last times he was seen in the original series was when Ben used him in a beach episode. Surfing.
Although occasionally this could be subverted, as shown in Ripjaws last appearence in the Original series, where he proceeded to start tearing chunk out of a bad guy's car, despite being in the desert and the car MOVING.
Weaksauce Weakness: He can't survive without water for long. As a result, he is one of Ben's least used aliens.
In the original series, this is quoted as Ben exclaims that Upchuck is a bottomless pit, but just can't eat regular food.
Breath Weapon: Upchuck can fire laser beams from his mouth (or as he called them in Upchuck's debut 'exploding loogies'), though it has only been used twice (first against the Forever King in the original series then later on against Chromastone (who had escaped from the Omnitrix) in alien force. Though he prefers to fire exploding green energy pellets instead.
The Cameo: Made a brief appearance in "Victor: The Spoils", while Ben was unconscious, before making his official reappearance in "Prisoner 775 is Missing".
Skunk Stripe: Ultimate Wildmutt has one down his back. It's even got a black outline where it attaches to his back, making it more obviously this trope.
The Voiceless: Averted with Ultimate Wildmutt, who is able to talk.
Aliens Unused Since Alien Force
Since the Ultimatrix is just a better Omnitrix, most of these have been confirmed to be in it, but not accessed yet.
The Artifact: Echo Echo pretty much makes this guy obsolete.
Badass Adorable: An adorable alien that's around the height of a kid who likes praying pranks. However it was used to destroy an army of mutant bugs in its debut episode.
Weaksauce Weakness: The clones all feel each other's pain. If one dies...
Eon (Race Against Time)
See Villains section
Eye Guy (OS-48)
Early-Bird Cameo: Appeared in an alternate scene of Secret of the Omnitrix's opening scene but chronologically appeared first in "Ben 10 vs. The Negative 10, Part 2".
Arch-Enemy: To Ben. Runs in the family, before Ben, he considered Ben's grandfather Max his archenemy.
To the point that in the Grand Finale of Ultimate Alien, Ben is more worried about Vilgax than he is about Diagon. And rightly so.
Big Bad: Original series season 1,Secondary Big Bad in Seasons 2,3,& 4, Secret of the Omnitrix movie, and Alien Force season 3. He also serves as the True Final Boss of Ultimate Alien. Basically for the entire series.
Cthulhumanoid: Worth note is he's actually mistaken for another Great Old One in Ultimate Alien.
Didn't See That Coming: His biggest flaw. His defeats always result from something he didn't expect to happen and he has difficulty dealing with it when it happens.
The Dreaded: Is considered the most dangerious being in the entire universe and feared by nearly everyone. The only time anyone hasn't feared him was Diagon, who Ben was less worried about than Vilgax. And rightly so.
Expy: To some degree, both series may have been trying to model him off of Darkseid, with the first series having a generally merciless murderer, and was feared by almost everyone in the galaxy, in Alien Force, he owns his own world, and even has what seem like the Omega Beams.
He also seems to be an Expy of Cthulhu, as he has a head of an octopus and green skin but has no wings, but unlike Cthulhu, he is being mistaken for another Great Old One rather then being a Great Old One.
Dangerously Genre Savvy: He spent a lot of time studying the Omnitrix, giving him the ability to turn it off whenever he wants to. He also exploits Ben's inability to not go to areas where evil's afoot. Most of the time he fails is because, as detailed above, something that he never expected happens.
Knight of Cerebus: Any episode he had some sort of presence in, the tone would become less humorous.
Lightning Bruiser: He moves amazingly fast even after he uses the implants to make his arms stronger, which makes them swell up.
Sadistic Choice: In "Secrets", he attacks the Rustbucket and holds Gwen and Max hostage, and would only let them go if Ben handed himself over. Ben relented.
Villainous Breakdown: It's subtle, but every time Vilgax appears after the season 1 finale, he's slightly more erratic, and he gets progressively more hellbent for the Omnitrix on Ben's wrist, then again, when you're a galactic overlord constantly getting beaten down by a kid, his grandpa, and his cousin, that does guarantee a breakdown.
Made much more obvious in The Movie. He goes from just going after the Omnitrix to being bent on killing Ben to get it. This is the result of him being thrown into the Null Void, which he displays a Twitchy Eye whenever its mentioned. This goes so far that he turns up a chance to get the Omnitrix if he shuts down its self destruct (which he's probably smart enough to do so) and saves the universe because it doesn't involve killing Ben.
Alien Force
Even Evil Has Standards: subverted; his respect of the Galactic Code in Vengeance of Vilgax was, if anything, Pragmatic Villainy, as it allowed him to easily conquer 10 worlds without wasting any ressource and gain several new powers in the process. In the following episodes, he has no problem breaking said code.
Kneel Before Zod: attempted this on Ben in the finale after he took the Omnitrix from him. It didn't work.
Mega Manning: Begins defeating heroes across 10 worlds and absorbing the powers of those he defeated.
Noble Demon: it's implied in Ghost Town that he actually cares to some extent about his people. Unclear if he really was this or if it's just his Villain with Good Publicity status.
One-Winged Angel: Though not quite as frightening as it could potentially be, as seen here.◊ According to Word Of God, he could always do this, but there weren't many situations were it would actually come in handy.
Fortunately for him, this form happened to fit the description of the alien worshipped by the Flame Keepers Circle, allowing them to play them as pawns in Ultimate Alien.
Somewhat of a shame that Remar was used in the show and not DiMaggio, as the former sounds nothing like Vilgax from the original show, while the latter does an impressive Steven Blum imitation.
Villain with Good Publicity: Implied to have gone that route since the Card-Carrying Villain persona didn't fare well for him. It worked out pretty well for him, as it let him conquer 10 worlds in a fairly short length of time.
Deal with the Devil: Makes a deal with Diagon, an Eldritch Abomination, to free it from its can in exchange for the power to conquer the universe. Unfortunately for Diagon, he wasn't the devil in the deal.
Eviler than Thou: Diagon realized too late that Vilgax was not to be underestimated.
Did You Just Scam Cthulhu?: he successfully manipulated Diagon by faking submission, letting him kill George and eventually use a machine brought by Psyphon to absorb him, gaining his powers.
The Starscream: Ben instantly realized Vilgax wouldn't submit to this unless he had something up his sleeve. He was right, Vilgax let Diagon kill Sir George and beatdown Ben and company before stealing his power, absorbing Diagon in the process.
Elite Mooks: The Flame Keepers' Circle are a lot more dangerous than his old Mecha-Mooks.
Exact Words: Vilgax assures his most loyal follower that's he going to "transform" the Earth.
Vilgax: When I'm done with this planet, you won't recognize it!
God Guise: Was mistaken for the alien worshipped by the Flame Keepers' Circle, Diagon the Knowledge Bringer. He's just enough of a Manipulative Bastard to make complete use of this, gaining a group of very competent minions with Undying Loyalty towards him. This does have a drawback, however, as only his One-Winged Angel form resembles Diagon and he can't revert to his normal form in their sight. Bonus points as Diagon is named after an actual pagan god and a Great Old One.
How The Mighty Have Fallen: Subverted. While he's lost his empire (since he was declared dead, it ended up crumbling without him) and is trapped on Earth, he's gained a legion of suprisingly competant and dangerous henchmen who have Undying Loyalty towards him.
MacGuffin Delivery Service: His obsession with gaining Diagon's power causes him to deliver its heart's power back to the Eldritch Abomination, despite Ben warning him that him was being manipulated.
Manipulative Bastard: Weakened from his previous battle, he gladly played first the role of a sideshow freak to regain his strength and then as Diagon, an alien worshipped by the Flame Keepers' Circle, to get himself a personal cult of followers that would do absolutely anything he desired. He even managed to trick Julie into working for him for a short time.
And again after Ben defeated him and took Diagon's powers from him, he tried to corrupt Ben by convincing him to use it to go Knight Templar. He almost succeeded.
Nice Job Fixing It, Villain: Diagon was crushing the heroes with little effort...until Vilgax made his move and absorbed his powers. His own ego pretty much does the rest.
Not so Different: Vilgax invokes this with Ben in the finale, claiming they both use power to impose their will on the universe.
Out Gambitted: Diagon thought he was in control of Vilgax the entire time. He wasn't, Vilgax was really the one manipulating Diagon the entire time.
Psyphon
Avenging the Villain: attempts this on Ben to avenge Vilgax's apparent death. He fails.
Evil Genius: he appears to be an brillant scientist and often is the one building devices for Vilgax.
Not So Harmless Villain: for most of the series, he was a rather passive character, usually leaving his master do the fight while he sticked to scientist and servant purpose. During the episode where he attempts to avenge Vilgax, however, he proves to be a surprisingly effective fighter who can stands toe to toe with Ultimate Spider-Monkey.
Smug Snake: he is extremely arrogant to anyone other than his master, including Ben.
Undying Loyalty: he is incredibly loyal to Vilgax, going as far as trying to avenge him after Ben apparently killed him, and kept serving him even after his empire falled apart. Considering Vilgax is not above threatening him occasionnally, this truly is loyalty.
Even Evil Has Loved Ones: Played with; he is ruthless and quite abusive to Charmcaster in the original series, but openly admits he does care about her in Ultimate Alien (though he still refused to come and help her, believing it was suicide). According to Word Of God, their relationship is complicated.
Freudian Excuse: The destruction of his people and home by Adwagia. Of course, as the Dark is Evil example above shows, he let it get to him in a negative way much more than his niece Charmcaster did.
Defrosting Ice Queen: In "Where the Magic Happens", she becomes slightly more friendly to Gwen as the episode progresses. Sadly undone by "Enemy of my Frenemy", which makes her more of a Broken Bird than before.
Dimension Lord: She becomes the ruler of Ledger Domain after defeating Adwaita.
Do With Him As You Will: In "Couples Retreat", after finding out Dark Star was just using her for her power, she takes it all away from him and leaves him at the mercy of the heroes.
Enemy Mine: Gwen convinces her to help them retrieve a piece of the Map of Infinity from her home before Aggregor does. They fail.
Freudian Excuse: She was raised by her uncle, who is shown to regularly threaten her if she doesn't obey him. Gee, is it any wonder she turned out bad?
The fact that every other human from her home was killed, including her father, doesn't help any either.
Heel Face Revolving Door: In Ultimate Alien. She's bad, then good, then worse, then neutral but working toward becoming good.
Karma Houdini: Sure, Gwen takes pity on the poor broken girl, but no sort of lawful punishment after attempting mass genocide? Isn't that....odd? Though she did have the entire reason for everything she'd ever done give her a What the Hell, Hero? speech and be put forever out of her reach, so it's likely that Gwen and the others decided that punishing her would just be cruel.
In all fairness, she does have power on a level exceeding Gwen's at her command. Perhaps it felt it best not to provoke her when she had just killed all three of them without a sweat.
Kick the Son of a Bitch: She betrayed her uncle for her own evil goal, but Hex definately had it coming.
Sucking out Adwagia's soul for her Deal with the Devil. While her other victims were innocent and didn't deserve it, he certainly did.
The end of "Couples Retreat". Charmcaster is good with this trope.
Not So Harmless Villain: Though it wouldn't seem like it given many of her past performances, she manages to rack up a body count only the Highbreed and Vilgax have managed to exceed, and they have entire armies. She even killed the heroes, something no other villain has managed. The body count was only temporary, as all her victims get brought back from the dead shortly afterward, but that hardly detracts from the fact that she pulled it off.
Took a Level in Dumbass: Seems to have happened to her as of ''Ultimate Alien.' In "Couple's Retreat", she's acting like The Ditz. Granted, she does have the motive of wanting to fill her now-empty life with ANYTHING, even a giddy, girlish love for Darkstar, but still....
Took a Level in Jerkass: She wasn't nice in the original, but she's much bitchier in Alien Force, especially to her golem minions.
Villainous BSOD/Heel Realization/My God, What Have I Done?: After she makes a Deal with the Devil to revive her father by sacrificing all the souls in her home world, he tells her she's become She Who Fights Monsters and he doesn't want to be revived at the cost of some many other lives, which makes her cry as she realizes he's right. He breaks the deal, undoing everything, leaving Charmcaster completely crushed, the one thing she'd spent her entire life trying to obtain now forever out of her reach.
A Father to His Men: Sir Cyrus, leader of the fourth Forever Knights faction, is extremely protective of his men.
Ancient Conspiracy: A very complex one. One faction believes the conspiracy is to kill an Alien Dragon, another thinks its to use alien tech to conquer the world, and yet another thinks its to follow the path of "The First Knight" who founded them.
Big Bad: The Forever King; Driscoll, who was Forever King in the original series, is half the Big Bad of the fourth season (Vilgax being the other half through the "Secret of the Omnitrix" three-episode movie.) and Old George for season 2 of Ultimate Alien.
Enemy Civil War: To date there are at least four Forever Knight factions, all of which think of the others as frauds. Each has their own Forever King, in order of appearence: Driscoll, Patrick, Urian, and Cyrus. This was lampshaded in one episode where Ben and company had to ask which faction the present group they were facing were with. Turns out they were with the fourth faction they hadn't met yet.
Recently Old George, said First Forever Knight, returned and untied all four factions.
Evil Counterpart: To the Plumbers, especially in the original series.
Faceless Mooks: Exaggerated in "Reflected Glory" when we see Knight with his helmet on, while brushing his teeth.
Fantastic Racism: Quite literally their mission statement; its just after Old George left last, they sorta drifted off onto other goals. Until he returned.
From Nobody to Nightmare: Driscoll started out as just a veteran Plumber, but after being outed as someone using alien technology for his own selfish reason, joined the Forever Knights, then managed to work up the ranks, becoming the Forever King.
Let's Get Dangerous: Thanks to Old George, they've gone from four splintered and laughable factions to a deadly force with Powered Armor forcing aliens to either leave the planet or die, to the point where Ben has to threaten to kill every last one of them to get them to retreat.
Noble Demon: Enoch on occasion, particularly the "Ben 10" video game in which he tries to stop Vilgax and save the world, though using extreme measures to do so.
The Ultimate Alien groups also have traits of this, teaming up with Ben and company on occasion.
Hypocrite: Doesn't like aliens living on his planet, even if they're just average people that do no harm. His legend was created when an alien gave him the most powerful weapon ever created-that he created-without which George could never have beaten Diagon.
Immortality Immorality: Averted. Despite living for so long George holds tight to his ethics and founded an order to defend Earth from alien threats and Diagon in particular. If anything, he has theopposite problem.
Noble Demon: Despite being a xenophobic Knight Templar, he actually does have a sense of morals and honor.
Not so Different/Shadow Archetype: To Ben. Both are humans who use an Amplifier Artifact created by Azmuth, have similar issues with trust from those they protect and possess rather high opinions of themselves. The key difference is that Ben doesn't see any difference between humans and aliens while George is a champion for humanity only. The similarities between the two even cause Ben to allow George the chance to take on Diagon despite Azmuth's orders - but when he fails, Ben says he gets the sword of Ascanlon to finish the job.
Bad Boss: when Dr Vicktor slightly questions the reason for pursuing Ben, Zs'Skayr beat the crap out of him before explaining him that Ben shouldn't be underestimated.
Big Bad: Original series, season three (though it was unknown until the finale).
The Chessmaster: is revealed to have put a Thanatos Gambit intended to resurrect him that serves as the main plot to season 3.
Family Unfriendly Death: He is exposed to sunlight and bursts into flames, burning to ashes. This happens twice!
Hey, It's That Voice!: Has the same as Ghostfreak (Blum in the original series and Bennett in Alien Force).
Hijacked by Ganon:Dr Vicktor, the Yenaldooshi and the Mummy were all three revealed to be working for him.
Hive Mind: his conciousness works that way, to the point it can survive even in the smallest sample of his DNA. He uses it both to keep surviving and to create an army of Ectonurite minions under his control in "Ghost Town".
What Happened to the Mouse?: The Zs'Skayr we know is a clone of the original resulting from his DNA being added to the Omnitrix. After having his DNA sampled, nothing is mentioned as to what became of the real Zs'Skayr.
Just looking at it in a Pensieve Flashback causes Ben, Gwen and Kevin to freak out. Consider what they fight on a daily basis and that says a lot about how horrible it is.
Eviler than Thou: Finds out too late that Vilgax was this to him.
Healing Factor: at several points in The Ultimate Enemy, his injuries heal as soon as he gets them.
Out Gambitted: Though he was the one pulling Vilgax's strings, only to find out too late it was the other way around the entire time.
Reality Warper: he displays abilities such as creating an acid rain, size-shifting, stripping George of his immortality
Sealed Evil in a Can: Was imprisoned in his universe by Old George. Justified as cutting his heart out wasn't enough to kill it so there weren't many other options.So now he's trapped in Azmuth's sword.
It's been confirmed on the credits of "The Enemy of My Frenemy" that HE was the "Old One" who was willing to accept 600,000 souls.
Diagon may have ultimately sealed inside Ascalon when Ben uses to to steal his power from Vilgax, if he wasn't killed by Vilgax absorbing him.
World Wrecking Wave: When he comes close to being freed, one of these is set off, turning every unprotected human on Earth into his minions.
He's Back: He reappears in the actual series in "Ben 10,000 Returns".
One Shot Character: For Ben to use with the Omnitrix, since he's not in it anymore. Justified in that "Race Against Time" was canon, but not with the main timeline.
Shout Out: His plan in "Ben 10,000 Returns" is rather simular to the Big Bad in The One. Wiping out and absorbing all alternate versions of themselves.
Tomato in the Mirror: He and his minions are all revealed to be Ben Tennyson, of an alternate timeline. Though since the Eon from the movie intended to turn Ben into a new Eon, we can't be sure he's the original Eon.
The Highbreed
All Your DNA Combined: After Ben recalibrates their genetic makeup, this is what happens.
The Blank: their face possess no visible features other than several red eyes that don't even move, making you wonder if they even are actual eyes.
Dying Race: the real reason behind their invasion; they wanted to destroy the universe because they were too proud and didn't wanted to die alone.
Easily Thwarted Alien Invasion: played with; the heroes are unable to stop their invasion using force, and Ben has to solve the conflict peacefully by solving their Dying Race problem so they won't feel the need to destroy the universe anymore.
Fantastic Racism: to the extreme; when one of them got bitten by Humongousaur, he claimed to have been infected, and that he had to leave and disinfect the whole zone. By killing everything around of course.
Irony: They wished to wipe out all species save their own due to their inevitable extinction, but now they have become amalgamated with those very races.
Knight of Cerebus: to the saga as a whole; the beginning of their story arc in the first two seasons of Alien Force marked the point where the saga went into a Darker and Edgier tone, and they were truly menacing and oppressing villains. Similarly, after the end of their story arc, Alien Force suddenly changed tone to get more humorous.
Cassandra Truth: Victor Validus tried to warn the Plumbers the Hive were preparing to attack but no one believed him until the invasion was already started.
Hive Queen: The queen of the hive serves this role. However, she's also the only one able to reproduce like a real insect queen and killing her takes the Hive with her.
I Am Legion: The Hive's hosts refer to themselves as 'we', even the Queen's host despite the fact she refers to herself in the singular.
Enemy Mine: Helps Ben and his friends against the Highbreed invasion, teams up with Kevin to gain an artifact only to betray him afterwards, and helps out again in Ultimate Alien's first season finale, only to make a failed backstabbing attempt in the end.
Evil Counterpart: To Gwen (similar powers) and Kevin (similar personality).
Light is Not Good: As Mike Morningstar, who not only was beautiful and blonde, but his powers were mostly represented by golden/yellow light. As Darkstar, his powers now are obviously dark energy, but he once almost regained his original appearence, and presumably his powers.
Manipulative Bastard: To Gwen in his debut appearance, and later to Kevin, and later to Charmcaster.
Subverted in "Aboslute Power", in which the heroes are completely prepared for his manipulation and inevitable double-cross.
Names to Run Away From Really Fast: "Morningstar." Sometimes used as a divine title for Jesus. More commonly used as the translation of "Lucifer" into English.
Not so Different: Points out in Ultimate Alien that he and insane Kevin are the same. Kevin confirms this later by calling Gwen "Lovely Gwen", Darkstar's name for her.
Sort of an odd example of Viewers Are Morons, where they're expecting someone older or smarter (like Gwen is supposed to be) in the Periphery Demographic to catch it, but to a little kid, he has a good-guy-sounding name.
That Man Is Dead: "Michael Morningstar no longer exists. Now I am Darkstar!"
All There in the Manual: Before the second series, the pop-ups in the first series confirmed Sevenseven's existence. They're also brothers (with Sevenseven obviously being the elder).
Ineffectual Sympathetic Villain: You can't help but feel bad for the guy, stuck in a human body that causes him no end of grief.
"Double Or Nothing" all but spells this out: by only wanting to turn back to normal, he's (d)evolved into a HarmlessAnti-Villain.
Hoist by His Own Petard: Gets himself attached to a Cassiopeia dream eater he meant for Ben.
Insufferable Genius: As a Galvan he's extremely intelligent and helped build the Omnitrix so he does have smarts, but he insults and demeans everyone else from Ben to Azmuth to Vilgax as he believes himself to be the most brilliant being in the universe. Not surprisingly this comes back to bite him in the ass repeatedly, especially in the series finale of Alien Force.
Body Horror: His first use of Galapegus' powers involves multiple vents opening on his body. YMMV on how it compares to Ultimate Aggregor.
Brought Down to Normal: Thanks to Kevin absorbing his powers. It's assumed he can still absorb matter and energy since that's considered "normal" for Osmosians.
Evil Counterpart: To Kevin. As noted below, he is very similar in role and personality to Kevin in the first show, as well as being of the same species, with the same powers and love of absorbing energy. Kevin seems to be aware of how similar they are, and has apparently taken this to heart given how intense he is about stopping him.
Expy: Aggregor is basically Kevin if he didn't reform: sadistic, merciless, and with the power to absorb energy, complete with his body mutating to accomodate the stolen alien power.
Fake Boss: Kevin ends up becoming the final enemy to face in Ultimate Alien's first season.
Hidden Agenda Villain: His true goal, to reshape the universe the way he wants, was kept hidden until his last appearance.
Meaningful Name: He aggregates (collects) the powers of other aliens.
Mega Manning: His base power allows him to steal the abilities, and apparently life force, of whoever he touches. However, he can only use the stolen power at a tenth of its original strength, and it wears off. He's built a machine to subvert this, fully and permanently absorbing the power of the five aliens he's hunting at the cost of killing them.
Strawman Political: Though a blender of several political pundits (as one message board noted: he's like the worst of Bill O'Reily, Keith Olbermann, Glenn Beck, Al Franken, and even Stephen Colbert mixed in a blender.)
Villain with Good Publicity: More like Incredible. Despite many problems in his smear campaign against Ben, he not only manages to somehow avoid being arrested by the feds, but also seems to still have enough of a following to keep his show.
Carl Nesmith/Captain Nemesis/Overlord
Even Evil Has Loved Ones: his feelings for Jennifer Nocturne were apparently sincere, or at least became so.
Expy: he wears similarities with both Warp from Teen Titans and, to a minor extent, Iron Man.
Green-Eyed Monster: the major reason for him turning evil was because of his jealousy toward Ben. Ironically, Ben didn't mean to ruin his reputation and was actually a big fan of him before he turned evil.
Fallen Hero: he started out as a superhero, but ended up trying to cause fake kidnapping in order to get popular again, and eventually turned into a criminal due to his jealousy toward Ben. Both Ben and his Agent hinted he had been an actually great hero before.
Pet the Dog: surrendered so his accomplice Jennifer Nocturne could get medical attention.
Shoot the Dog: he was one of the few villains in the show to be explicitly hinted to have killed human beings. At one point, he even killed an innocent driver just to steal his car.
Ninja Pirate Zombie Robot: He is, as some plot descriptions on websites gave him: A Zombie Vampire Clown.
Our Vampires Are Different: in his first appearance, he fed of people's happyness. The result when he got all of it wasn't pretty.
Same Character, But Different: In the first series, he has a very supernatural edge to him. Ultimate Alien made him out to be an incredibly Joker-esque character with none of the powers he demonstrated in the first series, though he still has the same overall personality.
Beware the Silly Ones: as hard as it is to admit, they can be pretty dangerous due to their massive weaponry. Though if you think about it, it's precisely the fact they are truly silly that makes them dangerous...
Even Bad Men Love Their Mamas: They really respect their mother, Ma Vreedle. Too bad she considers them as failure (not that we can object her...).
Heel Face Revolving Door: In their first appearance in Ultimate Alien, they're attending the academy to become Plumbers. However, the next episode they're in they are back to being thugs. Gwen scoulds them for this, and they return to Plumbers shortly after.
Leeroy Jenkins: they basically don't know how to solve any problem without blowing up things.
Me's a Crowd: it's revealed in Con of Rath that there are actually a whole army of Vreedle Brothers, since they are actually clones created by their parents through a kit.
Too Dumb to Live: a ridiculously extreme exemple when they shoot a fusion grenade at Kevin. In a space station. When Argit points out that will not just kill Kevin, but everyone on the station, including them, Octagon admits he "didn't consider this".
Khyber
A bounty hunter who will apparently serves as the main villain in season 1 of Ben 10 Omniverse.
Big Bad: of Omniverse (at least season 1, it seems).
Derailing Love Interests: Julie has become much less nice since the start of Ultimate Alien. Some of this is having to deal with Ben being famous (it was very justified in the episode w/ Captain Nemesis), but she's showing new traits such as being overly competitive and short-tempered that weren't originally present, possibly as a misguided attempt at giving her more flaws.
She joined what was effectively a cult in "Flame Keepers Circle." She thought it was a corporation that was trying to improve people's lives by introducing alien tech at a faster rate than the Plumbers wanted (despite Kevin and Ben both warning her that such an act typically destabilized planets). It was really a bunch of crazy people worshiping Vilgax, and it was ridiculously clear too, but she grabbed the Idiot Ball firmly until it was beyond obvious she was wrong.
And yet in the next episode they brought back Elena, crazier than ever, and had her impersonate Julie as a "perfect girlfriend" for Ben as a sort of Take That to shippers who hate Julie for reasons like her not accommodating Ben enough.
Jeff Bennett: Save for his debut in "Secret of the Omnitrix".
Not so Different: He's immature, selfish, cracks jokes at inopportune times, but when it comes down to it, he can be helpful... sort of like Ben. This is all the more obvious when he says that he likes Ben for saying that he didn't want to figure out how to work the Omnitrix better (or, more specifically, allowing Ben to change forms at will within alien form).
Same Character, But Different: Was a lot more sarcastic and cynical when we first see him in Secret of the Omnitrix, but is more stoic and serious (though retaining a sense of humor) by the time of Alien Force. Justified in that there was a five year Time Skip in-between appearances.
Call Forward: Word Of God said that in Race Against Time (a movie that's otherwise questionably canonical), Paradox guarded the Hands of Armageddon from Eon for several years until Ben stopped him.
This is finally revealed in Ben 10,000 Returns. The movie was actually part of 'cross-time' and thus Paradox guarded that alternate timeline's Hands of Armageddon
Hero of Another Story: Is apparently constantly on adventures of his own and the first time he appears, its stated he's already saved the world hundreds of times.
Immortality: Type II. Due to existing outside of time, he can't age and apparently also doesn't need to eat or sleep. This also makes him immune to time manipulation to some degree (he can't be aged into dust or anything like that, but he still feels it to some degree).
Offscreen Teleportation: Has this ability due to 'finding shortcuts' in time. Though he's also very capable of onscreen teleportation.
Brick Joke: Pierce is the only one whose appearance doesn't come from any Omnitrix alien. Turns out he's from Argit's race (Argit demonstraded a shooting-quill ability in "Andreas' Fault").
Expy: Manny, Helen and Alan are half-Tetramand (Fourarms), half-Kineceleran (XLR8), and half-Pyronite (Heatblast) respectively. Pierce's powers are also reminiscent of a certain needled X-Man.
The Other Darrin: Cooper has been voiced by Cathy Cavadini, Corey Padnos, and Chris Pratt, though given his gradual physical changes as he ages, this makes sense.
Sacrificial Lion: Pierce's cold blooded murder by the Forever Knights showed just how merciless and dangerous they'd become.
What Could Have Been: Cooper would have held Kevin's place after the Time Skip, but according to Dwayne McDuffie, it was Murakami who had Kevin become the new teammate instead.
Tetrax
The Atoner: He was the one responsible for giving Vilgax the crystal that inevitably became Vilgax's tool for destroying Tetrax's planet.
Took a Level in Badass: in her first appearance, she was a naive girl who could barely stand a fight. The next time we see her, she can fight toe to toe with Arachnichimps Dnaliens.
Others
Cash and JT
Butt Monkey: Whenever they appeared in the original series, Ben found the time to give them a mega-wedgie.
"The Reason You Suck" Speech: Courtesy of Ben in "The Gauntlet." After they spill a smoothie on him as a prank, he chides them for pulling the same nonsense since grade school and admits disbelief that he used to be afraid of Cash.
Combo Platter Powers: Ra'ad throws lighting, has telepathy, enters electronic devices by becoming lightning and enters pretty much anything else by becoming liquid. And bodyjacking, which Ben himself never bothered with but the king of Zarcovia can somehow channel to put his own soul in the body of Dr Viktor.
Galapagus takes his name from the well-known Galapagos tortoise (and possibly the Galapagos Islands since they, like him, have remained uncorrupted by the outside world)
P'andor refers the story of Pandora's Box.
Andreas is obviously a reference to the San Andreas Fault.
Sharing a Body: Rather like Ghostfreak, Ben's first use of Ra'ad leads to this temporarily.
