History YMMV / DigimonFrontier

** The conflict between the Human-type and Beast-type Digimon which ''effectively started the events of the plot'', according to the backstory for Cherubimon, is supposed to be an ongoing war by the time the series begins, yet it is never elaborated on aside from a single movie, and a [[NonSerialMovie non-serial]] one to boot.
** Lucemon's origins. Unlike the villains of many previous incarnations, he's never given any sort of backstory or explanation as to where'd he come from, how he'd become evil, outside of an admittedly fitting sense of pride.

* WhatDoYouMeanItsForKids: As usual in the franchise, ''Frontier'' could be definitely very hardcore for a show which was marketed to children in many countries. The new humanoid Digimon ensured the hand-to-hand was often savage, many villains were intimidating either for how they looked like or just for how shockingly dangerous they were, a Digidestined was [[spoiler:killed (even if he got better)]] onscreen, some of the characters's backgrounds dealt with topics like bullying and parental divorce. While ''Anime/DigimonTamers'' might take the cake for the least family-friendly due to Konaka's foreign fandom and psychological touches, this series had actually little to envy.

* WhatMeasureIsANonBadass: We're supposed to treat [=MagnaGarurumon=] and [=KaiserGreymon=] as badasses who transcend the Warrior Ten, who are all but indicated to be {{Physical God}}s. In the show itself, the two ''frequently'' get steamrolled by foes that they theoretically could beat without degenerating into uphill battles (even discounting the Royal Knights, they have trouble dealing with three [=SkullSatamon=] at one point) and even the battles they won are won only barely. The end result is the two having the worst win rate out of any anime protagonist's Mega forms (4 wins, 5 losses and 2 draws for [=KaiserGreymon=] and 3 wins, 6 losses and 2 draws for [=MagnaGarurumon=]) and making them look like ''failures''. It doesn't help that the duo wasn't seen again after Lucemon unceremoniously throws them around one last time.

** The Loser Evolution [[note]]The theme tune for Transcendent Evolution "The Last Evolution" is ridiculed by Japanese fans for being a ''loser's theme'' because the Transcendent Evolutions of Takuya and Koji have an infamous rep for losing nearly every major confrontation they come across or fighting uphill battles if they win before they get unceremoniously dumped by Lucemon and were never used again. It goes to the point where they are more like oversized {{Butt Monkey}}s with their "Transcendence" being more like an InformedAttribute. The only time where this theme is used in a winning battle, it's when Susanoomon fights Lucemon but it's not even the full version unlike the losing battles.[[/note]]

** [=LordKnightmon=] ships [[{{Twincest}} KouKoucest]]!

** The Loser Evolution [[note]]The theme tune for Transcendent Evolution "The Last Evolution" is ridiculed by Japanese fans for being a ''loser's theme'' because the Transcendent Evolutions of Takuya and Koji have an infamous rep for losing nearly every major confrontation they come across and in the case they win on their own, it's an uphill battle. It goes to the point where they are more like oversized {{Butt Monkey}}s with their "Transcendence" being more like an InformedAttribute.[[/note]]

** Related to the previous, there's some diversity on opinions about the show's storytelling. While one side praised it for doing an excellent job at making the villains a credible threat, especially compared to previous seasons, the other side criticizes it because this had the side effect of spawning potentially endless {{Filler}} arcs where the heroes would fail at achieving anything decisive, including Izumi being infamously defeated in her own power-up episode or the "Transcendent" [=MagnaGarurumon=] and [=EmperorGreymon=] being defeated '''seven episodes in a row before they were soundly floored by Lucemon and never seen again''', the latter which earned its status as free game for ridicule in the Japanese fandom like ''Anime/DigimonAdventureTri'', where even ''Anime/DigimonXrosWarsTheYoungHuntersWhoLeaptThroughTime'' are otherwise treated with at most a neutral stance.

** Related to the previous, there's some diversity on opinions about the show's storytelling. While one side praised it for doing an excellent job at making the villains a credible threat, especially compared to previous seasons, the other side criticizes it because this had the side effect of spawning potentially endless {{Filler}} arcs where the heroes would fail at achieving anything decisive, including Izumi being infamously defeated in her own power-up episode or the "Transcendent" [=MagnaGarurumon=] and [=EmperorGreymon=] being defeated '''seven episodes in a row before they were soundly floored by Lucemon and never seen again'''. It tells when ''Frontier'' is considered free game for ridicule in the Japanese fandom like ''Anime/DigimonAdventureTri'', where even ''Anime/DigimonXrosWarsTheYoungHuntersWhoLeaptThroughTime'' is treated with at most a neutral stance.

** Related to the previous, there's some diversity on opinions about the show's storytelling. While one side praised it for doing an excellent job at making the villains a credible threat, especially compared to previous seasons, the other side criticizes it because this had the side effect of spawning potentially endless {{Filler}} arcs where the heroes would fail at achieving anything decisive, including an instance of one of the heroes being infamously defeated in her own power-up episode.

** A [[Anime/DigimonTamers Gallantmon]] appears as cameo in Autumn Leaf Fairs. That's right, a ''cameo'', without any lines, in a series which introduced the concept of the Royal Knights. The American dub tries to fix this a bit in that the Gallantmon speaks in the same manner as in ''Tamers'' and even refers to itself in the plural as a definite ShoutOut to ''Tamers'', but that's still not much.

** Murmukusmon is main antagonist of [[Recap/DigimonFrontierMovieslandOfLostDigimon the movie]]. Arriving to the Island of Lost Digimon long ago, Murmukusmon obscured an ancient tablet about Ornismon to trick the populace into revering the monster as a benevolent legend. Posing as d'Arcmon and Hippogriffomon, leaders of the Human and Beast Digimon respectively, he strokes constant civil war through powerful rhetoric, convincingly feigned emotion, and appeal to their pain, causing many allies from all sides to revert into Digi-Eggs, and thus excess Digi Code, when defeated. By the time the [=DigiDestined=] discover his ruse, Murmukusmon acquires all the code he needed, reveals his deception and the true history, and initiates Ornsimon's revival. Cold and calculating, Murmukusmon played everyone for fools and schemed to conquer the Digital World with his new living superweapon.

** Murmukusmon is main antagonist of [[Recap/DigimonFrontierMovieRevivalOfTheAncientDigimon the movie]]. Arriving to the Island of Lost Digimon long ago, Murmukusmon obscured an ancient tablet about Ornismon to trick the populace into revering the monster as a benevolent legend. Posing as d'Arcmon and Hippogriffomon, leaders of the Human and Beast Digimon respectively, he strokes constant civil war through powerful rhetoric, convincingly feigned emotion, and appeal to their pain, causing many allies from all sides to revert into Digi-Eggs, and thus excess Digi Code, when defeated. By the time the [=DigiDestined=] discover his ruse, Murmukusmon acquires all the code he needed, reveals his deception and the true history, and initiates Ornsimon's revival. Cold and calculating, Murmukusmon played everyone for fools and schemed to conquer the Digital World with his new living superweapon.

** A sizable contingent of fans considers ''Frontier'' to be the franchise's DorkAge thanks to a combination of a GenreShift into an animated HenshinHero series, the abandonment of the beloved partner Digimon and thus the entire {{Mon}}s concept, and the fact that it [[ToughActToFollow came right after]] [[GermansLoveDavidHasselhoff the (now) much-lauded]] ''Anime/DigimonTamers''. On the other hand, a smaller contingent of fans praises it for taking ''Digimon'' back to its ''[[Anime/DigimonAdventure Adventure]]'' roots while still being its own beast, and at the same time for daring to go in new directions instead of recycling storylines and plot points from ''Adventure'', as ''Tamers'' is sometimes accused of doing. The humans getting their hands dirty ''actually fighting'' instead of being a walking evolution battery for the enemy to exploit is considered one of the biggest draws of ''Frontier''.

* This also extended to the series' enemies. Out of the first five recurrent ones, [[spoiler:Grumblemon]] was always a pain to merely last against even in random scuffles and it took ages to defeat him, [[spoiler:Mercurymon]] literally [[spoiler:one-shotted the BigGood of the series in the latter's very introduction]] and then went to do little until his own battle, and [[spoiler:Duskmon]] was just a plain NightmareFuel who seemed he could never be defeated. For the last arc, after the heroes had received several power boosts, the Royal Knights wiped the floor with them episode after episode without any apparent advance, playing YouCantThwartStageOne at its finest before the arrival of Lucemon. But even ''then'', [[spoiler:when the heroes had unlocked power to match Lucemon's, they continued taking scary beatings every time Lucemon unveiled a new form, and it ended up with the Legendary Warriors having to pull basically a TakingYouWithMe against him.]]

** Izumi/Zoe is probably one of the biggest examples of this in the whole franchise. On the one hand, her fans like her for her and her Digimon forms [[MsFanservice good looks]], [[AllOfTheOtherReindeer having a relatable backstory]], [[FriendToAllLivingThings her gentle personality]] and some good ShipTease moments with Takuya. Her haters on the other hand, dislike her for being the [[TheChick token girl]] character with {{Stripperific}} Digimon forms, the first of which was [[FauxActionGirl easily defeated]] in its ''own debut episode'' and the second of which didn't fair much better.

* AlternativeCharacterInterpretation: Regarding Cherubimon, the reason why he was corrupted by Lucemon is stated to be because he was discontent with Seraphimon and Ophanimon favoring Human-type Digimon and discriminating against Beast-type ones. However, it should be noted that most of his grudge is directed at Seraphimon, being much more lenient with Ophanimon (he caged her instead of simply killing her, spared Seraphimon on her request and even [[WeCanRuleTogether offered her rule the Digital World with him after he would get the Legendary Spirits]]). In the flashback detailing his fall into the darkness, Cherubimon also appears observing Seraphimon and Ophanimon together with a disdainful expression, seemingly envying their good relationship. With all this, it may be that Cherubimon turned to the dark side because he was in love with Ophanimon and he resented Seraphimon for getting along with her , which made him more susceptible to Lucemon’s corruption. Izumi/Zoe also seems to buy this theory, as she mentions the possibility when Ophanimon tells the Chosen Kids the story.
* AntiClimaxBoss: There are many awesome fights in ''Frontier'', but [[spoiler:Mercurymon]]'s duel with Takuya, although quite artsy and interesting in its own right, ends up unfortunately being a little too one-sided from both sides. While he does dominate in the first minutes, [[spoiler:[=ShadowSeraphimon=]]] gets utterly humiliated at the moment Takuya unlocks Aldamon, first by failing to make him even flinch and then by being taken down with a single, weak-looking attack, and his next round as [[spoiler:Mercurymon]] ends just as quickly, with more power being spent on the battlefield itself than on him. Fortunately for Mercurymon, he gets a more climatic showdown with the protagonists as Sephirotmon/Sakkakumon.

** Arcs in ''Frontier'' tend to drag, as the writers often aimed to reduce the PlotArmor trope to the thinnest and create the most drama with what material they had, and it is commonly felt that they sometimes went just too far and made the entire series a borderline FailureHero show as a result. The Velgemon and Cherubimon arcs are long, but by the time the Royal Knights come around and curbstomp the leads episode after episode without much advance, some fans just put their foot down or skip to the ending.
** This also extended to the individual enemies. Out of the first five recurrent ones, [[spoiler:Grumblemon]] was always a pain to merely last against even in random scuffles, [[spoiler:Mercurymon]] literally [[spoiler:one-shotted the BigGood of the series in the latter's very introduction]] and then went to do little until his own battle, and [[spoiler:Duskmon]] was just a plain NightmareFuel who engaged constantly with Koji and seemed he could never be defeated. For the last arc, after the heroes had received several power boosts, the Royal Knights wiped the floor with them episode after episode without any apparent advance, playing YouCantThwartStageOne at its finest before the arrival of Lucemon. But even ''then'', [[spoiler:when the heroes had unlocked power to match Lucemon's, they continued taking scary beatings every time Lucemon unveiled a new form, and it ended up with the Legendary Warriors having to pull basically a TakingYouWithMe against him.]]

** It's a commonly held belief amongst fans that the other group of children the group meets were intended to have the other four Legendary Warrior spirits. While a few hints of this can be found, it's never outwardly stated that this is the case, although considering how much the series was rushed towards the second half and [[WhatCouldHaveBeen how many ideas were left on the cutting room floor]], there's no way truly know what the plan might've been.

** Lucemon is full of symbolism. Not only is he clearly inspired by [[{{Satan}} Lucifer]][[note]]His name derives from the French word for "light"[[/note]], his attack is called "Literature/ParadiseLost Punch". Also, he has what looks like a ''Dharmachakra'' (Buddhist Wheel Symbol) on his chest in [[OneWingedAngel Chaos Mode]].

** The ElementalPowers of the first five Chosen Children? Same as those of the FiveManBand from ''Anime/SmilePrettyCure'', only the elements of the leader and the lancer are swapped. As if that wasn't enough, one of ''Smile'''s villains is a WolfMan with a color palette mostly in cool colors (just like Wolfmon/Lobomon and Beowulfmon) and often gets paired with the light-elemental heroine in fanart.

* ItsTheSameNowItSucks: Ironically, despite the general TheyChangedItNowItSucks reaction to the HenshinHero concept, many viewers criticize this series for trying too hard to invoke nostalgia for ''Adventure'' from other directions, to the point that the characters comes off as fast copies of the original cast (and this is only exacerbated by the two lead characters being the SpotlightStealingSquad just like Taichi and Yamato). This could be considered a FranchiseOriginalSin, as it was also a complaint that was in ''Tamers''.

* PresumedFlop: The fact that ''Digimon'' fell out of fad more or less at the time ''Frontier'' ended has caused the popular belief that the latter was a complete failure in ratings and sales, but it is not really the case. While the series did fail at making noise, this was (and still is) the usual for the franchise in Japan after the ''Anime/DigimonAdventure'' continuity was closed; in reality, ''Frontier'' did not do much worse than ''Anime/DigimonTamers'' in any field, and still attracted almost twice the ratings later received by ''Anime/DigimonDataSquad'', which was the series that finally got the franchise out of its traditional broadcaster Fuji TV.

* HollywoodHomely: Calmaramon. From the characters' viewpoint, she's much less attractive than Ranamon and causes her Toucanmon entourage to ditch her. In reality, barring her squidlike bottom half, she's ''really'' not that hideous. In fact, she looks like a much more slimmed down version of [[WesternAnimation/TheLittleMermaid Ursula]]. [[https://wikimon.net/images/0/0b/Calamaramon_collectors.jpg Her EX card]] in ''Digimon Collectors'' even emphasizes that she can be just as cute as Ranamon is.

** Some people actually ''like'' that [=LordKnightmon=] was renamed Crusadermon and [[ShesAManInJapan made female]]. While [=LordKnightmon=] ties into its evolution line, Crusadermon better expresses its usual KnightTemplar nature and is [[AwesomeMcCoolname just a really cool name]].

* GeniusBonus: The fight between Korikakumon and Asuramon is framed not only in their respective elements, but also in the inspirations for their forms, that of the Yeti and an asura respectively. In Tibetan Buddhism, asuras are demons, while Yetis are animals, yet animals human enough that some currents consider them capable to actually follow Dharma (an example of this being the famous Pangboche Hand, a relic that supposedly belonged to a Yeti that served Lama Sangwa Dorje).

* AntiClimaxBoss: There are many awesome fights in ''Frontier'', but [[spoiler:Mercurymon]]'s duel with Takuya, although quite artsy and interesting in its own right, ends up unfortunately not being one of them. While he does dominate in the first minutes, [[spoiler:[=ShadowSeraphimon=]]] gets utterly humiliated at the moment Takuya unlocks Aldamon, first by failing to make him even flinch and then by being taken down with a single, weak-looking attack, and his next round as [[spoiler:Mercurymon]] ends just as quickly, with more power being spent on the battlefield itself than on him.

* ValuesDissonance: Japanese divorce laws are very different from those in other countries, since a family is considered as 100% split when the parents divorce, and tend to effectively discourage, if not prohibit, contact between its former members. As a result, Koji's father [[spoiler:hiding Koichi's existence, pretending that the twins' biological mother is dead, and effectively cutting off that side of the family]] comes off as a lot more of a jerk move overseas, when he probably was trying to [[spoiler:spare Kouji from what he saw as needless suffering coming from not being easily able to meet his mother and brother per law.]] The American dub does try to lighten this up by softening some of his dialogue about [[spoiler:Koji's birth mother and stepmother.]]

** A [[Anime/DigimonTamers Gallantmon]] appears as cameo in Autumn Leaf Fairs. That's right, a ''cameo'', without any lines, in a series which introduced the concept of the Royal Knights. The American dub fixes this a bit in that the Gallantmon speaks in the same manner as in ''Tamers'' and even refers to itself in the plural as a definite ShoutOut to ''Tamers'', but that's still not much.

** This also extended to the individual enemies. Out of the first five recurrent ones, [[spoiler:Grumblemon]] was always a pain to merely last against even in random scuffles, [[spoiler:Mercuremon]] literally [[spoiler:one-shotted the BigGood of the series in the latter's very introduction]] and then went to do little until his own battle, and [[spoiler:Duskmon]] was just a plain NightmareFuel who engaged constantly with Koji and seemed he could never be defeated. For the last arc, after the heroes had received several power boosts, the Royal Knights wiped the floor with them episode after episode without any apparent advance, playing YouCantThwartStageOne at its finest before the arrival of Lucemon. But even ''then'', [[spoiler:when the heroes had unlocked power to match Lucemon's, they continued taking scary beatings every time Lucemon unveiled a new form, and it ended up with the Legendary Warriors having to pull basically a TakingYouWithMe against him.]]

** While also being FanficFuel, the unused "Fusion Evolutions" of Thunder, Ice, Wind and Darkness (Namely Rhinokabuterimon, Daipenmon, Jetsylphimon and Raihimon) are very well-liked by the fandom, notably because they would have help Izumi, Tomoki, Junpei and Koichi not being sidelined.
* FanficFuel: The unused fusion evolutions for the four other kids as well as the non-existence of fusion evolutions for the other elements (Wood, Steel, Water, Earth) which allow every fanart and fanfic possibilities. Not to mention the four lost kids the group find in a certain episode (Tommy's bullies) who are often used as teammates with the group with the aforementionned spirits.

** The chanting part of the English dub theme song doesn't have any official lyrics and might even be gibberish, but the fanbase has unanimously interpreted it as "I am the One".

** [[spoiler:Mercuremon's "stage opera"]] against Takuya.
** Sakkakumon, known as Sephirotmon in Japan, is shaped like the ten aspects of God in UsefulNotes/{{Kabbalah}}, the [[MeaningfulName Sephirot]]. Fittingly, that's the same number as legendary warrior spirits; and each orb contains one enemy corresponding with one of the ten elements. One of these orbs contains Mercuremon. Yes. Mercuremon exists inside ''himself''.