* SugarWiki/AwesomeMusic: The Pack's theme song.
* BrokenBase: Albeit not as bad as its [[WesternAnimation/{{Ben10}} sister show]], the older fans that are outside of the target demographic have made numerous complaints about how the 2nd season wasn't as serious as the 1st. The younger fans within the demographic, on the other hand, are completely fine with the show's current state.
** As of Season 3, the pendulum seems to have [[CerebusSyndrome swung back around]].
* CompleteMonster:
** Van Kleiss is the ruthless dictator of Abysus. Though he uses propaganda to claim he's trying to build a better world for E.V.O.s, in actuality Van Kleiss cares only for his dream of world domination, and nothing for his subordinates. Van Kleiss makes a habit of [[TakenForGranite petrifying E.V.O.s]] by sucking the nanites out of them, or [[TragicMonster turning regular people into E.V.O.s]] to act as muscle for him, not caring that such an action could leave them permanently transformed. In his bid for power Van Kleiss murdered Rex's parents, experimented on his WoobieDestroyerOfWorlds follower to amplify her powers while causing her excruciating pain, and threatened a little girl to force her father to turn the people of New York into his zombie army.
** [[{{Fantastic Racis|m}}t Hunter Cain]] kills E.V.O.s left and right even when Rex is trying to ''cure'' them. Then he uses his goon squad to piss Rex off in an attempt in discrediting him, and finally, he [[MoralEventHorizon clones E.V.O.s to lure Rex out, was prepared to sacrifice his own men, and then tried to ''murder'' Rex when he was unarmed.]] In his next appearance, he tries to slaughter a whole lot of children.
** [[MorallyAmbiguousDoctorate Dr.]] [[CorruptCorporateExecutive Branden Moses]] from season 2's "A Family Holiday" announced a breakthrough in nanite research that allowed him to dramatically reverse E.V.O. mutations, giving a faux demonstration using an E.V.O. and either an actress with a set of prosthetic tentacles or an E.V.O. with tentacles, playing the part of the "cured E.V.O." Having convinced hundreds, possibly thousands, of people (including Dr. Holiday, who added her sister Beverly Holiday to Brandon's ranks) that he had made a breakthrough, dozens of intelligent but physically deformed, incurable E.V.O.s lined up to be cured. Instead, they were kidnapped and brought to a lab in the Arctic circle where their mutations were amplified and were ready to be [[{{Greed}} auctioned off to the warlord with the deepest pockets]].
* CrazyAwesome:
** Gatlock, the pirate leader in "Badlands", who spouts such lines as "Fire the Ion Cannon Thingamabobs!" while performing raids in tricked out ice cream trucks.
** No Face, as well. He's clearly off his rocker, but he can kick ass when he gets involved.
* DarknessInducedAudienceApathy: While the show isn't EXTREMELY dark, this trope seems to have had an effect limiting the show's international appeal as compared to Ben 10.
* DracoInLeatherPants:
** Van Kleiss seems to get some of this, mainly from fans who view [[KnightTemplar White Knight]] as much more of a CompleteMonster.
** It's lessened as Van Kliess has crossed the MoralEventHorizon more and more and White has gone DefrostingIceQueen on us (not to mention [[spoiler: his replacement, Black Knight, being even worse than him, and his being kicked out of Providence giving him further CharacterDevelopment.]]
** Breach gets this treatment also. She's sympathetic and [[spoiler: gets a HeelFaceTurn,]] but that doesn't just change the fact that she's a pyscho who has done some really messed-up things.
* EarWorm:
** Considering how short it is, the theme song is actually pretty catchy. The [[http://www.youtube.com/watch?v=ks0kMQ9flZI extended version]] is even better.
* EnsembleDarkhorse: Everyone likes Breach.
** Captain Callan has his own fan club on Website/DeviantArt.
** There are quite a significant amount of fans who admit to [[JustHereForGodzilla only watching the show for Agent Six]].
** Now it seems that Gatlocke may be becoming one of these.
** [[FanNickname Nightshadow]] perhaps.
* EvilIsSexy: Black Knight, big time.
* ExecutiveMeddling: For the ConspiracyTheorist in you, this might be the reason that JohnCena had to step down from voicing Hunter Cain in episodes after the debut. It's a shame because Cena [[HeReallyCanAct did a surprisingly good job]], but it's probably likely that WWE executives didn't want their number-one draw (whose primary audience is little kids, mind you) connected to an AxCrazy, [[{{Hypocrite}} hypocritical]], [[FantasticRacism fantastic racist]]. That…or [[StatingTheSimpleSolution Cena's WWE schedule is just too time-consuming to make time for voice-acting.]]
* FanNickname: "Sleevespace" seems to be the popular term for the sleeves in which Six keeps his fold-out katanas.
* FanPreferredCouple: Despite the ShipSinking, the age difference, and Rex himself being a ShipperOnDeck for 6/Holiday, you'll still find [[MayDecemberRomance Rex and Holiday]] to be one of the most popular pairings in the fandom.
** There also seems to be a good amount towards Rex/Breach.
* FoeYay: Gatlocke and Rex. Every other sentence in Gatlocke's fight with Rex was something like "Oh, I like that!" or "I've got a serious case of Evo-envy!"
* GrowingTheBeard: Many feel that the show has been getting better since the second half of season 1 started.
* HarsherInHindsight: At the end of "A Family Holiday," after Six [[spoiler:nearly dies]], he and Rex have a HeartwarmingMoment in which Rex tells him, rather affectionately, never to do anything like that again. Seems like a throwaway line until [[spoiler:"Six Minus Six," when we see what happens the next time Six jams his magnetized blades into a machine]].
* HesJustHiding:
** This pops up every time Van Kleiss apparently dies, due to [[JokerImmunity obvious reasons]], but the best example is [[spoiler:Breach]]. When you apparently kill off the [[spoiler:EnsembleDarkhorse]], you better believe this'll happen! Note that [[spoiler:while Dr. Holiday is skeptical that she's dead, Van Kleiss seems to have moved on and is looking for a replacement]].
** [[spoiler:She's alive!]]
** Some may be hoping that[[spoiler: Rylander is still out there.]]
*** [[spoiler: He is...though he's currently a deformed subject in a lab tank.]]
* HilariousInHindsight: The episode "{{Film/Gravity}}".
* InferredHolocaust:
** In "The Swarm", the population of Beijing is said to be around 15 million. As a quick reference, the current population of Beijing is around 18 million... yikes! It puts into perspective just how bad the world actually is...
** To make it worse, in "The Plague" a plague puts ''everyone in the world'' into a coma (except the E.V.Os). Rex outright acknowledges that a lot of people must have died when no one is around to pilot anything/control any disasters/etc. Rex can't cover the entire world, after all.
** The City of Kiev aka the Bug Jar, all E.V.O.s had been absorbed by Alpha, which could effectively mean that they're [[KilledOffForReal dead permanently]] seeing as any on screen absorption had KILLED the victims. Happened during the Ben 10 crossover.
* InformedWrongness:
** Characters increasingly get critical and distrustful of Providence despite the fact that [=EVOs=] present a clear danger to the entire world, Providence has two [=EVOs=] working for them (one with a criminal record), and Cure, contain, or kill really does seem like the only viable approach to problem [=EVOs=]. Not to mention we never see Providence so much as threaten to cure, contain, or kill a human EVO that isn't threatening others.
** It's mainly due to White Knight's {{Jerkass}} tendencies.
* JerkassWoobie: Breach gets this status in her title episode. Sure, she's an evil, possessive kidnapper, but when her [[spoiler:pocket dimension is being trashed]] by Rex and the Creepy Girl, they're essentially [[spoiler:''tearing her mind apart'']]. Regardless of the situation, you had to feel sorry for Breach there.
* MagnificentBitch: Black Knight, full stop. From posing as a ReasonableAuthorityFigure, keeping her own true power hidden to use at later date when necessary, playing politics with the Consortium, and pulling off a success starscream to gain supreme power, she's fit the bill big time.
* MemeticMolester: Van Kleiss is ''very'' creepy when he tells Rex how "special" he is or how much he needs him.
* MoralEventHorizon: [[spoiler:Providence under Black Knight]] crosses it in "Back in Black" when they employ MindControl technology to deal with [=EVOs=], [[spoiler:even sapient ones.]] [[spoiler:Cesar Salazar]] definitely crosses it when he tries to use this technology on [[spoiler:Rex, his ''own younger brother''.]]
** Van Kleiss' treatment of [[spoiler: [[TheWoobie Breach]]]] is definately this for him.
* NightmareRetardant: The series is pretty on-and-off on how seriously it treats its premise (which honestly sounds like something from a post-apocalyptic horror movie), but it definitely butts heads when the hero is fighting Lovecraftian horrors to a rock theme and stock sound effects.
* ParanoiaFuel:
** Nanites:
*** In the show's universe, they're everywhere, in ''everyone'', and at any second you or someone you know could end up an EVO. Pleasant dreams!
*** Things go FromBadToWorse: The nanites infested every ''living'' thing. Meaning anything from algae colonies on up to trees and animals (this actually happens!) could turn into an EldritchAbomination out to waste you. Suddenly your backyard looks a little more worrying...
*** It makes one wonder what would happen if something like a [[NighInvulnerable tardigrade]] [[SmallTaxonomyPools or a]] [[GiantEnemyCrab mantis]] [[PowerFist shrimp]] ended up becoming an EVO.
*** Or if the symbiotic bacteria that live in someone's gut suddenly went EVO without the person going EVO... considering how [=EVOs=] tend to get big and go on destructive rampages... *shudder*
** Eggs are a reproductive cell, so there's the horror of the implication of reproductive cells going EVO. But then this is taken a step further. It's common practice for some egg farms to incubate all their eggs for 3 days after Laying, those that show any kind of development get sent to hatcheries, those that don't get sent to market. it's not uncommon for a developing egg to slip into the market batch (it's not unheard of to find half developed chicks in grocery store eggs). So think of the implications if this practice is still in play in the Generator Rex universe. Those eggs seen in "Moonlighting" could have been EMBRYOS. Think of a world where embryos could go EVO at anypoint in their development.
** Then consider the implications of a ''pregnant mother'' going EVO. What happens to the fetus?
*** What happens when the fetus goes EVO and the mother doesn't?
* RelationshipWritingFumble:
** Despite Circe and the rest of the Hong Kong gang denying it, they do seem to get awfully close to each other WHILE they're proclaiming themselves as 'just friends.' It helped that the boys decided to make their move after it, though.
** Certainly intentional, as the RunningGag in that episode was basically them confusing the ''hell'' out of Rex.
** Then Played Straight, because in that episode, Circe was trying to get over her troubled past life, changing her appearance, and flirting with Sqywid, when Rex brought up their past, she got a little upset, and by the end of the episode, it appears She and Sqwwid are going to become an item, and she seems to end her relationship with Rex. In later episodes her appearance is back to normal, and she still likes Rex, her relationship to Squwid is never brought up, outside of a throwaway line where he tells her to escape and leave them.
* RescuedFromTheScrappyHeap: White Knight was somewhat divisive among some of the fanbase until "Plague", when he helps Rex and gives out some relatively justifiable reasons for being so distant and bitter, [[SugarWiki/MomentOfAwesome while also accumulating cool moments]].
** [[spoiler: Recent events have just made things better for him, seeing as he recieves further CharacterDevelopment and PetTheDog moments.]]
* TheScrappy:
** Some find Bobo difficult to tolerate because he's more a liability than a help usually and he does a lot of questionable things that he is never reined in for by Providence. Plus a talking, smartmouthed monkey seems [[MoodWhiplash a bit out of place]] at times when the show is dealing with some pretty serious and disturbing things.
** There are also some who don't much care for Circe (alot of them being [[FanPreferredCouple Rex/Holiday shippers.]])
* {{Squick}}: Rex's reaction after he cures the first monster, and the old guy hugs him. The ''naked'' old guy.
** Circe's face when she's using her powers. Borders on NightmareFuel.
** Rex's nanite overload and the nanite monster in "Frostbite".
** A bit of unintentional squick, that hopefully the creators did by accident. ZAG-RS [[spoiler: is programmed with the voice of Rex's late mother.]] He also has the hots for Doctor Holiday. Both are voiced by GreyDeLisle. So, when you think about it [[spoiler: Rex has the hots for a chick who sounds exactly like his mother.]]
** In ''Heroes United'', Ben uses Upgrade to merge with Rex, becoming a full-body suit inside and out. One hopes his tactile sensation as Upgrade is rather low.
* TearJerker: The majority of "Six Minus Six."
** [[spoiler: Breach's goodbye]] from "Lions and Lambs."
** The last few minutes of "Assualt on Abysus".
* TheyWastedAPerfectlyGoodCharacter: After being cured, Beverly, Doc Holiday's little sister, ceased to be important until the filler episode "Rock My World" and even then it wasn't a big role. Considering that Rex got over his crush on Doc Holiday because Beverly was closer to his age, she could've served as a non-EVO love interest for Rex or even become a trio with him and Noah.
* TheyWastedAPerfectlyGoodPlot: "Operation: Wingman": [[spoiler:Who else thought that Annie was the EVO-Bunny, and all of her "accidents" during the date were genuine attempts to kill Rex?]] Jossed since it was stated that she's like that with ''every'' date, but still...
** The episode ''ran'' on RuleOfFunny, [[spoiler: if she was the EVO]], it probably would have ruined [[SugarWiki/FunnyMoments the otherwise hilarious]] episode.
** [[spoiler:Rex's two giant robot builds. The first form is obscured in shadows, and is only alluded to about twice in the series outside of flashbacks. He never uses it. It would have been nice to have a few episodes showing Rex being forced to use it in a desperate situation, and fully considering the ramifications of it, rather than seemingly rushing it in the final episode. His second giant build seems to be less a full use of all builds than a generic giant robot, which doesn't use any of his Omega-Nanite builds. ]]
* WhatDoYouMeanItsNotSymbolic: [[spoiler: The remains of Breach's restraints]] in "Breach" look suspiciously like a broken heart.
** Of course, we also have things like Providence (the name suggesting divine intervention, if not outright God) and an infection of Nanites that is in everyone and everything (much like sin, in the orthodox Christian sense).
* TheWoobie: Holiday after we find out what happened [[spoiler:to her sister]], especially in "A Family Holiday."
** "Lions and Lambs" turns Breach (formerly a JerkassWoobie) into a full-on Woobie. Oh so very much.
* WTHCastingAgency: There's HyndenWalch as Breach for starters.
** To be fair Hynden also voiced Ace from ''JusticeLeague'', so it wasn't that bad of a choice.
** Also, who decided that ''JohnCena'' got a voice acting role?
*** Considering that John Cena is damn good on the mic, and actually did a pretty good job, I'd say it wasn't that bad of a choice.
*** Sadly a case of voice-actor WeHardlyKnewYe, as Cena was replaced by JohnDiMaggio in subsequent episodes.