#p.m. rambles

Comparisons to Adventure are inevitable here, given how the two are directly connected. So for starters we just want to say that Adventure is really damn good, but it’s villains really boil down to “here’s a villain - now here is an even stronger and badder one you gotta defeat”, which is a problem 02 managed to fix in the best ways possible

So, let’s go! 

Ken Ichijouji!

He is one of the fan favorites for a damn good reason, because right from the get-go, 02 makes a twist to its villains compared to Adventure. Adv starts with Devimon who was just some Bad Guy (I am sorry to all his fans to trash on him, he served his purpose well enough storytelling-wise but he was forgotten as soon as he was gone), but Ken?

This is a child. A direct parallel to our main characters. The last season’s entire thing was about the Chosen Children being the ones to banish evil, so it is already an interesting starting point to think what if one of those kids IS the evil. And boy, evil he is. He enslaves Digimon and builds the dark towers to expand his territory in the Digital World as the Digimon Kaiser, but this is still a real child with a family and life outside of the Digital World. The main characters just cannot kill this guy like Adv gang did with Devimon and the others, and besides that, Ken is successful and well-respected in the human world, so his disappearance would not go unnoticed. The main characters really can’t go telling Ken’s parents, police or the like about what this kid is doing, because after all, he isn’t doing anything heinous in the real world, and to Ken, Digimon aren’t real.

And of course with him being a Chosen Child, he has a partner of his own, Wormmon, who loves Ken unconditionally even in his villainous ways, so seeing the abuse Wormmon gets from Ken really pulls your heartstrings. You begin hating Ken, but simultaneously rooting for Wormmon to get his happy ending.

And then, after multiple crimes against Digimon, he is defeated. This kid realizes the error of his ways, that these creatures he saw as a mere part of a game were living, breathing creatures - his Wormmon included. The spell is broken, and Ken succumbs to deep despair. And you, as the watcher, first get the euphoria of seeing this little turd be knocked down from his high horse, only to be kicked in the guts with the pain and sympathy you feel towards him, as he watches Wormmon vanish from his arms. After all, he is just a child, and should never have been involved in this sort of thing.

The writers could had stopped here with his arc and have him just be some kid on a power trip, but they decide to go a step further with his backstory - we get the episode about his past with Osamu, his now-dead older brother, and they decide to sprinkle some gifted child syndrome and survivor’s guilt to the mix as well. There’s an entire story arc of Ken being in the Digital World before the events of 02 which was not handled in the anime too much, but we are not gonna dig deeper into that now, but keep this in mind for later!

Eventually, Ken does come around and join the main cast as a fellow Chosen Child, but that is not done in the span of a single episode - he has to earn the trust of the main cast, and he regrets his past actions for the rest of the series. But with Wormmon reborn on his side, he is now on the path to healing. We dare to say that Ken is the real main character of 02, but his villain arc is the main factor that makes him as good as he is. 

We are not downplaying Daisuke’s role as the main character with that claim though -  Daisuke being just a normal untraumatized kid is the perfect parallel to Ken, who has had to endure all sorts of horrors. Daisuke was the first one to welcome Ken to the group after all, whereas characters like Iori took the longest time to warm up to him (but we’ll get more to him later)

So yeah, that’s Ken! The series is off to a great start here with its villains!

But Ken was only the first villain, surely, they cannot cook better than this, right?

This is where 02 surpasses Adventure in terms of its villains - 02 is not just a bunch of random characters thrown on a death row to be killed by the main kids, but it is a logical string of events, where you peel one layer off to reveal another layer of this series-spanning mystery just what the hell is going on here with the dark towers Ken had been building all along

Next up, we are introduced to Arukenimon, who is revealed to be the one (well, a one to be more precise) who got Ken to the entire Digimon Kaiser business to begin with, and takes off from where Ken left - continuing building the dark towers, and using them as her lackeys by turning them into soulless, fake Digimon.

She is historical when you think about it - she is the first major female villain in Digimon, and even if she is just a stepping stone to another character coming later on the list, she is fantastic in her own right with her personality and overall vibe. We love a bad bitch when we see one. It should also be noted, how she remains unsexualized through the entire run, which is a miracle of its own, given how Horny later Digimon seasons get with some of their female characters regardless of age

While her entire deal is a slow burn, she does immediately introduce a thought not handled too deep in the Adventureverse yet, with said thought being “why is an adult in the Digital World?” Indeed, why do we have Chosen Children, and not have the adults deal with these catastrophes instead?

It is not too hard to figure out that she is a Digimon and that is her reason for being able to be in the Digital World, and as much as we love her, a lot of her deeper character writing is down to speculation and headcanons, but that is another topic altogether.

And because socks always come in pairs, next up is Mummymon! He, like Arukenimon, is an extension to the main bad of the series, but to keep the main man a mystery till the time is right, Arukenimon and Mummymon are perfect for doing his evil deeds.

When Arukenimon finally gets defeated, the viewer immediately assumes that this is the end of her arc and someone else will now take her place like Adv did with its villains… But no! Now there’s two of them, and Mummymon enters the chat kicking ass immediately… Only to be shown very soon that he is just a silly goober who loves Arukenimon very much (speaking of love, it is one of his core characteristics, so it is very interesting how they decided to make this not-evil emotion such a crucial part of him)

Arukenimon started out as this dangerous and mysterious woman, but as soon as her counterpart Mummymon is introduced, she immediately turns into a girlfail, and from now on, Shenanigans ensue

As much as we dislike the comparison to Team Rocket, the two couples truly have the same energy, and we get to enjoy them from the moment they appear to (almost) the very end of the series, so the writers really put all their effort into making these two as enjoyable as possible. Arukenimon is so cool by herself, but her unhinged ways get to really shine when she is paired by this absolute dumbass of a man, but somehow these two walk the perfect balance between being a threat (perfect example are the scenes of Arukenimon with the pinwheel and Mummymon sitting on the swing) but also a couple of idiots (the entirety of the soup episode)

The two get so many little interactions that are not necessary to move the main plot forward, but it is these little non-plot-forwarding things that make characters more likeable and enjoyable in the long run. This is the reason why filler episodes and sidequests are important

With this being the late 90s/early 00s, this series falls to the trap of making their villains queer-coded though (which also adds more to the Team Rocket comparison), but we don’t really mind if one bit, given how well these two are written - after all, it is not stupid if it works.

While Mummymon’s core characteristic (besides love)  is to be kind of an idiot, he is shown to be smart in subtle ways: he is the one to introduce the concept of the Holy Stones in the series, and often ponders his (and Arukenimon’s) very existence, but his loyalty towards Arukenimon, and in turn Arukenimon’s unwavering loyalty towards their master stays unbroken, which ultimately ends up being their downfall. But we will get into that later.

Then, Blackwargreymon!

He is introduced to the series very soon after Mummymon, created from 100 dark towers by Arukenimon.

The towers are built to disrupt the balance between the human world and the Digital World, and a tool for Arukenimon to create disposable allies. All disposable but one: BWGreymon.

You know he is hot shit from the moment he spawns when he is a recolor of the strongest partner Digimon from the previous season, and almost as soon as he is born, he abandons his creator, deeming her weak. From that point forward, he is shown to ponder why he came to be: his fate simply cannot be the slave of someone else, right?

It is amazing how 02 takes many assets from Adv and makes them even better than what they already were: BWGreymon’s conversation with Agumon was phenomenal and it gave Agumon’s character writing a huge boost, but that alone wasn’t enough for him to find meaning in his existence. His journey is to find the purpose of Self, and he does so by destroying the aforementioned Holy Stones, trying to find an opponent worthy of himself, which he eventually finds, and along with it, he found Meaning... For now

He is probably more of an anti-hero than a villain, because he does march to his own rhythm, even if said rhythm does align perfectly with whatever Arukenimon and Mummymon are trying to accomplish at the moment

We’ll return back to BWGreymon later, for a while, he has reached a temporary peace of mind, but until we return to that: it is the time to move to the last but not least:

Yukio Oikawa. 

My god, this man.

His impact as a human villain is not as strong as it could have been given how we got Ken right from the get-go, but the way his story unfolds is just. Man.

The mystery behind Arukenimon and Mummymon is revealed to be this man, when he - this sounds bad out of context - kidnaps a bunch of children and copies this dark seed that was in Ken into them (this is where the aforementioned pre-02 Ken arc refers to, if you were wondering where did this thing come from all of a sudden), to further disturb the balance between the two worlds, this time from the human world's side

It is also revealed that he saw Ken at Osamu’s funeral, realized that Ken was a Chosen Child, and decided to use him as his pawn in the Digital World. But that failed, so Arukenimon and Mummymon were next to continue his work, until eventually he decided to take matters into his own hands. 

But… Why?

Before we move onto why this man fucks, let’s first mention how his presence also deepens the role of Arukenimon and Mummymon: previous villains and villains after 02 have had their lackeys too, but we don’t think any of them have quite reached the level of beloved these two managed to reach. So far they have seemed like a “let’s do evil for evil’s sake” type of deal, but with the main threat out of the shadows in the form of Oikawa, their mission is clear too: do everything in their power to help him succeed. Loyalty is a powerful thing.

We think now is also a good time to mention Demon and his gang who are just. Kind of There, but they are not in the pool of main villains of the series in our eyes, but merely there to boost the greatness of Oikawa’s character: Oikawa’s two lackeys have had their asses kicked constantly by the Chosen Children, and him suddenly appearing to the scene wouldn’t make them any stronger. So the introduction of Demon’s troops is a good way to show just how greatly Oikawa operates without him needing to confront the Chosen Children directly himself. This man has zero fear talking to this creature literally called “Demon”, he does not engage in unnecessary conflict with him or the kids, and ultimately succeeds at this mission with no casualties, with the kids having to deal with this Demon detour. He went "not my problem", let the kids deal with that mess, and leaves. So yeah, the Demon arc was good way to introduce him without making him too OP or having his ass handed to him.

But back to the main why of Oikawa:

Digimon has always been full of mature themes straight from its Adventure days, and they already perfected that sort of storytelling in its sequel not only with Ken, but with Oikawa as well. He is not written the same way the Digimon villains were in Adventure (monster of the week that wants to do evil), but the same way Ken is: what if one of the Chosen Children turned evil?

It is amazing how the writers managed to turn that question into two completely different storylines for its villains. A Digimon wanting to be evil for the sake of being evil you get, sure, they are monsters, even Ken you can see being a kid playing a game his way, but this seemingly random grown human man? Why would he possibly want to do this evil villain shit?

We’ve seen him be talked about more and more online as more time passes by the initial release of 02, because this is a character that was written by adults for adults: when we (not just me and Pupu here, but You as well) as kids didn’t seem to care about analyzing him too deep: we just wanted to see cool monsters fight, but he really hits different at an adult age. 

We have been the ones to see technology advance and evolve in the real time. He was born in the wrong place at the wrong time: Oikawa could see glimpses of Digimon, but he could not enter this fantastical world, because technology was simply too limited back then... And then he grew up. And an adult cannot be a Chosen Child.

He was never even given the chance to live up to his fate, yet he has to watch from the sidelines how these Adventure kids just end up in this situation he has wished for his entire life. In this very moment, we are Him. The writers played a long game with him, they waited 20+ long real life years for his story to kick in with us as adults watching this series. And it worked.

So he used all possible assets he could to work in the Digital World: he manipulated Ken to do his deeds since he was a child and therefore could enter there, he created Arukenimon and Mummymon, Digimon of his own to work there. For 50 full episodes, it was all Him that set this string of events in motion, and while 02 has its villains and their individual arcs, this is what we mean by it being a perfect string of events, because it all leads back to Oikawa.

And not only that, just like with Ken, the writers add extra salt to the wound: not only were his dreams crushed by the metaphysical impossibility of going to the Digital World with past technology, but the adults and his peers found these dreams silly and borderline ridiculed them. All of them but one: Hiroki, who would later on die, and truly leave Oikawa alone.

And now that we mentioned Hiroki, Oikawa’s appearance also gives much-needed lore to one of the main characters: Iori. He has been kind of There for most of the series, but this insane lore drop makes Iori easily surpass the other kids and make him the second most important Chosen Child right after Ken. Like god damn. Ties perfectly with Iori being this little hater, and suddenly needing to have this inner conflict with the fact that this man they have been fighting all along was his dead dad’s friend.

But we’ve seen a lot of people ask “why does he want to destroy the Digital World, if he so desperately wants to get there?” 

Well. A desperate man does desperate things, and there is one small thing that clouds his sense of judgement, but before that, let's go back to BWGreymon!

It is a nice twist to see that the main characters actually need to protect the Main Bad from getting killed by BWGreymon, because Oikawa is the one who knows how to un-seed the kids (another really bad out of context line to say here)

But wasn’t BWGreymon’s arc finished already? Why is he here again?

He got some sort of peace of mind earlier, but ultimately realized that his existence leads to Oikawa through Arukenimon: just like Mummymon ponders later on, he and Arukenimon are neither human nor Digimon, BWGreymon is a Digimon born from this weird mix’s powers and dark towers, but where did this hybrid and the towers come from to begin with?

Well, Oikawa, of course! Well, part of him anyway, because it is foreshadowed on multiple occasions that BWGreymon knows there is something - or rather, someone - wrong with this man.

Oikawa gets so close to finally creating this real human connection with Iori’s grandfather, his dead friend’s father, but is ultimately taken over by something. And in that brief moment, even BWGreymon, this creature running on pain and misery… Feels empathy. Towards Oikawa, the main villain, being tormented by this mysterious force. So he protects Iori’s grandfather from being attacked. And with that, BWGreymon sacrifices himself to protect the now-fragile wall between the two worlds. What a fantastic end to this fantastic character

But we are not quite finished yet! We actually lied before, Oikawa wasn’t the last nor the least, but a certain vampire is:

Oikawa finally gets what he wanted: to enter the Digital World. Turns out he got japed though, and he enters this hell dimension, where the aforementioned something ejects away from his body, and this something is no other than Vamdemon, back from the Adventure days.

Easily the best villain from Adventure makes a comeback in 02’s finale, and while it may appear random, it is hinted at multiple occasions before this moment through BWGreymon’s words.

I (P.M.) wrote a whole ass essay already why him living in this poor man’s brain is such a terrifying concept already, so we won’t be digging too deep into that here, but 02 enhanced an already great villain even further

But why him, and not the other, bigger villains after him, like Piedmon or Apocalymon?

He was already a huge threat in Adventure, given how he forced his way to the human world to make himself a physical, real threat to the kids’ homes. And given how Oikawa’s entire thing was that he was unable to go to the Digital World, it made perfect sense that the one villain who made a huge impact in the human world, would be the villain to reappear in the sequel. It didn’t seem to be hard to have this man to agree to be his vessel to try engulfing the worlds in darkness one more time

Vamdemon was already shown to be this cruel man who didn’t hesitate one bit to kill his subordinates, but also be sort of vain how it wasn’t - according to him - aesthetically pleasing to kill a bunch of children. We got an entire episode showing Gotsumon and Pumpmon just having gay old time, only to be killed by Vamdemon, but that episode’s problem was that we didn’t get to spend enough time with those two to care about them getting killed.

But who did we get to spend half a season with, seeing them in every episode?

Arukenimon and Mummymon. We refuse to find pictures to this part, because looking at them is very painful

While part of us think that it was poor/cheap writing to have them killed off so the writers don’t need to re-write them to change their evil ways because the two DID have potential for good… Killing two such beloved characters really did manage to do what the Gotsumon-Pumpmon episode tried to do: show just heinous this vampire fucker is. 

Having him also evolve into BelialVamdemon (which is a god-ugly thing in itself) shows that he no longer has a desire to keep up his class that he had in Adventure: he is here for straight-out murder. And murder he did, in the most cruel way possible. Arukenimon’s devotion to her creator (was it Oikawa? Was it Vamdemon? We are just as confused as she is) ended up being her demise, and Mummymon’s love towards her stayed strong till the bitter end.

This… Sucks big time. They deserved a more merciful ending, but then again, this is the type of writing that made us feel primal rage unlike anything has ever done before, which is good. Vamdemon’s crimes in Adv were just lowkey sexy, but he deserves 10 000 years in prison for the crimes he commits in 02. Here’s hoping they do SOMETHING with the spider and the mummy in that Digimon Adventure Beyond thing, because my god, they deserve their happy ending. Fuck.

So, all of the steps ultimately lead to Vamdemon: is it bad writing?

We’d say no! They took the best evil-with-no-motives villain from Adventure, enhanced him in the sequel, and made him create these tragic but forgivable villains, whose narratives were tied neatly to one another. And all of this lasted for the entire 50-episode run, with it never feeling rushed and no single arc overstayed their welcome.

Vamdemon wasn’t designed to be forgiven, and 02 made him even more heinous than what he was already in Adventure, but luckily the kids superkill this thing, avenging the best two characters in 02, saving the day.

But what about Oikawa?

He… Won? 

He did die at the end of it, but even if just for a brief moment, he did get to see his partner and my god, does the part with Pipimon hurt. We have been referring to him as Oikawa through this entire thing, but Pipimon… This little green thing called him Yukio. Can you imagine how long he has been waiting for those words. God damn.

The reunion ended up short though, because Oikawa was still actively dying, but at least he seemed content giving his last energy to restore the world he so wanted to be part of. And after all the evil shit he did through the entire thing… You still forgive him. We know we did.

And… That’s it, folks!

02 has its flaws, but its villains are easily its greatest asset, and we will remain being unwell about this for the rest of our lives

Let’s start with the basis of all character design: the colors!

Oikawa’s main color is purple, and it splits into its basic components in the form of red in Arukenimon, and blue in Mummymon. Keep these three colors in mind, because they are going to appear again further down in the analysis

We all know purple is often considered a royal color and is used a lot with villainous characters in media, so we don’t really need to explain why that was chosen for Oikawa. What is interesting though with Arukenimon’s red and Mummymon’s blue is the dynamic between those two colors: they are usually the main character - the secondary character colors when presented together, so it nicely shows what kind of hierarchy Arukenimon and Mummymon have in their relationship

But off to individual design analysis: Arukenimon!

Arukenimon’s disguised design has a clear witch-inspiration, which fits well with her hair-based abilities. While not pointy, her hat adds to the entire witch thing, and so do the upwards tips of her shoes.

She wears sunglasses, and she is not once seen without them in her disguised form. In Japanese culture, wearing sunglasses excessively is often seen as hiding something, be it one’s identity or true motives. This creates an air of mystery around her, and she does possess many secrets before the main characters or viewers get a hint of her motives or identity.

And what color are her glasses? Purple. She sees the world through Oikawa’s ideals, and she is his eyes, arms and legs in the Digital World, which are all colored purple.

The stripes on her hat share a similar design trait to her Digimon form, and with that, let's move to analyze the form in question!

The aforementioned Digimon form’s stripes are most likely inspired by the yokai tsuchigumo, which is said to have tiger-like stripes on its body. Her Digimon design is also very jorogumo-inspired, which is also a spider yokai, but almost exclusively depicted as a beautiful woman, who lures men into her den to be eaten. While these design elements are inspired by Japanese folklore, Arukenimon’s Digimon form has very Egyptian-based patterning and aesthetics, which is most likely to match with Mummymon’s design. 

Also note, how her glasses are now gone - her true nature is now for all to see.

Next up, Mummymon!

A friend pointed out how Mummymon’s entire look most likely has marching band inspiration behind it- the cane is a nod to the gun-crutch from his Digimon form, but it could also very well be based on a marching band baton. Marching bands also have a military history, and Mummymon does look like some sort of fucked up military priest, so the marching band allegations sound pretty plausible to us.

Mummymon’s coat has a slit on the back, which was a design choice originally made for horseback-riding, whereas speaking of Oikawa briefly here - his coat doesn’t have one. This may be me (=P.M.) looking too much into it from a seamstress’ perspective, but it is a nice nod to how Mummymon is a working man, and Oikawa is the boss who doesn’t need to do the heavy manual labor.

Returning briefly to the colors - Mummymon’s design has the yellow dots all around (including his eye), which are an opposite of purple, which is Oikawa’s - the main villain’s - main color. One could argue that those are the little glimmers of good/light that are in Mummymon despite him being assigned a villain, because he does question his very existence, the concept of a soul and such through the series. It also does look a little bit like stars in a night sky, which was an entire thing for him in a certain episode, but this part is most likely us looking too much into it.

The one-eye thing most likely ties to only one of his eyes being visible in his Digimon form, but we like to think he has lost his ability to look at some things three-dimensionally, hence his unwavering love towards Arukenimon despite her abuse towards him.

And then we. We have his Digimon form.

It fucks severely. This is peak Digimon insanity - the crutch that is also a gun, the entire Rambo-like aesthetic, and the leg lengtheners (or supports?) to this already lanky creature? Peak shit.

Another friend pointed out how the gun is an amalgamation of multiple real guns, but making a full chart of that deserves its own post entirely, so we are not gonna handle that here.

We couldn't figure out why the Egyptian theme was chosen for both Arukenimon and Mummymon though, given how Oikawa's entire thing is based on more gothic/vampire-like vibes. Speaking of him!

The man of the hour, Oikawa!

Can we just say how fucking rizzed this guy is? The coat, the fancy clothing underneath it, everything?

Oikawa’s coat has this patterning that subtly hints at the entire secret vampire thing he has going on, and the long coat really makes him look like some sort of a mob boss (which he kinda is with his two Digimon subordinates), with hints of his office job past underneath with his blouse, tie, etc.

He wears a red blouse, and like we discussed earlier here, red is Arukenimon’s color. Or perhaps it is blood red, hinting to Vamdemon? Can’t really say much does it have any symbolism behind it though, it was most likely just an aesthetic choice to go with the design’s main piece, which is the coat.

As for his non-clothing character design looks, it is an interesting contrast to see the length of Oikawa’s hair change between now with long hair, and before with shorter hair. The change of a character’s hair length is usually a symbol of change in their character, so in Oikawa’s case, it is not out of the realm of possibilities, that him letting his hair grown is a) a sign of depression and/or b) a sign that he quit his job entirely in his pursue of getting into the Digital World, so he no longer has the social pressure of keeping it short in an office setting

It is also amazing how a simple change like removing his eyebrows and making his skin sickly pale immediately changes his entire vibe, once the psychic vampire is out of his body.

And since we didn’t ramble enough yet, here’s a bonus brief BlackWarGreymon!

Opposing Arukenimon and Mummymon straight from his birth, he is colored with mostly greys, black, and again, yellow. Much like with Mummymon, yellow is opposite of purple and BWGreymon does nothing but oppose Oikawa and his gang, despite being created from the dark towers and by Arukenimon. He is born from darkness, but even this darkness has its light (and it creates a nice contrast to his main color black)

BONUS BONUS! Pipimon!

Pipimon is just a lil unripe tomato, but you can find some interesting things when you go check out some tomato symbolism: life, love, fertility, etc, so do what you will with that information. Maybe the lil guy being unripe is a sign of them never truly getting to go on an adventure with their tamer, because the time was never ready for the two of them?

We, as viewers, really didn't get the time to think or analyze this when The Reveal was made in episode 47 of 02 because the endgame started happening right away, but when you really start to think about it, everyone but Vamdemon was a victim in 02's cast, and I mean this with the aforementioned villains included

At first, the entire thing seems like "well this came out of nowhere" type of deal (especially if you hop into 02 without having seen Vamdemon in Adventure, which is not very good of an idea in general), but even if you see this scenario with no knowledge of what happened in Adventure, it does make sense to me at least after some thinking

It is pretty clear they chose Vamdemon as the parasitic entity mostly because he was a fan-favorite from Adventure (they did add Wizardmon in a previous episode too after all), but if you think about it on a meta level, it does make sense to make the vampire Digimon fill this role. Quoting straight from Wikipedia, "A vampire is a mythical creature that subsists by feeding on the vital essence (generally in the form of blood) of the living", and looking how Oikawa got like 20 years younger after having Vamdemon out of his body, yeah. It checks out. Vampires are often written to be cunning and charismatic too, so convincing an already desperate man to let him possess him also checks out

So here we have a situation, where a man who has already lost everything is offered even the slightest ray of hope, even if the said ray of hope is a curse in disguise. After the initial deal, Oikawa gets manipulated to hell and back without him even knowing it, but what is really interesting to me is to think about how Vamdemon saw things parasiting along the way

Vamdemon already hated humans, but getting to see actual human interactions and mankind's actions through the eyes of man probably didn't give him any empathy points towards them. Oikawa was presented as this Japanese salaryman, and if you do any research on how that working culture works in real life, the amount of social gymnastics demanded from Oikawa on a daily basis must have been a goddamn nightmare (or amusing) to watch from the sidelines. Either way, he was doing the man a favor, so Oikawa should be thankful to have this blessing - except when he was not.

What hurts extra much about Oikawa's arc is that he was so close to stopping whatever he was doing after talking with Iori's grandfather. He saw the path out of his misery, he had a real warm human interaction for the first time in years... But he never stood a chance. After all, he had this entity living inside him that knew everything going on in Oikawa's head, and it was going to exploit this to its fullest

So what was most likely happening on the background to keep Oikawa in check was way too many ways of manipulation to count: Vamdemon knows exactly what Oikawa wants or needs to hear to push him towards his goals, he knows precisely where to hit that will hurt the most, he convinces Oikawa to believe that he has nobody to trust but himself (and by extension, Vamdemon): his only friend is dead and the two consistencies in his life are but tools (in many meanings of the word) which leads me to!

I also want to point out how Vamdemon's influence also extends to Arukenimon and Mummymon - Mummymon's entire existence is obviously dedicated to Arukenimon, but Arukenimon dedicated her entire existence to Oikawa - never questioning his orders, even when Mummymon pondered about having souls and what they even are. She had unyielding faith and loyalty towards Oikawa, and honestly one could do a full analyze of the dynamic between those two (being his first creation and all), but the point is the two were deeply loyal to him, and that ended up being their demise. Vamdemon probably hated their guts, seeing how they are nothing but failures fighting against this new set of Chosen Children, which gives a nice explanation to Oikawa's hallucinations of the two calling him ugly, which I doubt the two would ever do in reality - that was most likely just Vamdemon's gaslighting campaign to not get too attached to these assets.

And once they got in the hell dimension? Vamdemon is out. Oikawa was nothing but a tool himself to be used, tossed aside as soon as he was no longer needed. Arukenimon and Mummymon are dead. This entire dynamic is of a monster who cares for nothing but his own goals and achievements, and does not hesitate one bit to exploit fellow Digimon and humans to get where he wants. And man does it hurt seeing almost every villain before him die due to this, villains that you have grown to love and emphatize with

Oikawa is a tragedy, and by extension so are Ken, BWGreymon, Arukenimon and Mummymon. Despite 02 having its fair share of issues in its writing, I will praise its villains and how they build up one after another thorough its entire run, ultimately ending up with this absolutely heinous and evil creature that you want to see defeated - no, you want to see him dead, because he has given the villains before him so much grief