Villains in anime come in every shape and size known to humankind. From some of the most over-the-top, theatrical, and melodramatic antagonists across the multi-verse to creepy, sinister, and mysterious. However evil and nefarious a character is, they still deserve to have that special someone. A person who they can talk to about all their evil schemes and complain about how their adversaries have thwarted them once again—a true friend who would stick by them through thick and thin.
Who would understand a villain better than another villain? These are just a few dastardly duos who could prove to be thick as thieves or get along like oil and water.
10 Foes: Muscular and Tsukasa Would Clash As Tsukasa Hates Adults
In a world of stone, might is what makes right. Tsukasa thought that if he could stop Senku from advancing science in Dr. Stone, then he would have the power to shape humanity in the direction that he wanted it to. Using the revival fluid formula, he brought back the strongest and toughest individuals that he could find. With that ideology, Muscular and Tsukasa would have been a great pair.
If it weren't for Tsukasa absolutely abhorring adults, that is. While Muscular may have super strength, he is also shown to be a murderous adult who takes pleasure in the killing and suffering of others in My Hero Academia, making him exactly the type of adult Tsukasa hates.
9 Allies: Yubaba and Sosuke Aizen Can Both Control The Human Mind With Ease
Yubaba from Hayao Miyazaki's Spirited Away and Sosuke Aizen from Tite Kubo's Bleach series would get along famously with one another. Both enjoy the incredible power to control the human mind with relative ease, and neither seems to have the scruples to find something inherently wrong with that.
In Bleach, Aizen famously controlled the Gotei 13 by murdering the Central 46 and using his zanpakuto's hypnotic powers to cover it up. Yubaba, on the other hand, used her powers like a mafioso, guaranteeing her slice of the pie from running the bathhouse in Spirited Away. Together, the world as we know it could collapse under their combined mental manipulation capabilities.
8 Foes: All For One and Dio Wouldn't Get Along As Dio Is Too Jealous
On a surface level, All For One and Dio both have a lot in common. They love power, have no problem using others to their satisfaction, and crave being on top. Being too similar, though, can also very easily breed disdain.
From JoJo's Bizzare Adventure, Dio has shown time and again that the simple thought of someone being higher up in the food chain than himself brings out a deep-seated rage from within, making a partnership between the two all but impossible to achieve.
7 Allies: Sukuna and Kurama Like To Manipulate Their Hosts
This would be a truly demonic duo. While later on in the series, Kurama, the Nine-Tailed Fox sealed within Naruto, was no longer considered an antagonist and, in fact, willingly came to help his host in a multitude of situations, he was not as kind in earlier seasons and reveled in toying with Naruto.
Sukuna from Jujutsu Kaisen is much the same in how he interacts with Itadori. Both only helping their host to further their own plans and machinations later down the road. All hell would spill if those two teamed out and were out and about.
6 Foes: Ulquiorra and Hisoka Are Polar Opposites
Ulquiorra from Bleach and Hisoka from Hunter X Hunter are polar opposites. Ulquiorra is a cold, calculated, mission-first individual who follows orders to a tee and does what has to be done. Nothing more, and certainly nothing less. Meanwhile, Hisoka is what some people would think of as the Goro Majima of the anime universe.
He follows the heat of the battle and is as unpredictable, or predictable, as it gets. Wherever there is a good fight is where Hisoka would go. Undoubtedly, this would drive the by-the-books Ulquiorra up the figurative wall and away from any partnership.
5 Allies: Jinno and Shishio Are Both Consumed With The Idea Of Revenge
These are two master swordsmen who are consumed with the ideology of revenge. Both of them believe in striking back at the thing that took what was precious to them and making it suffer. For Jinno, otherwise known as Jinnosouke, that was the Afro Samurai. The man who was once his friend whom he witnessed kill their sensei for his Number Two headband as children.
For Shishio Makato, it was the entire Japanese government that he once fought for. Ever since the shogunate attempted to kill him at the end of the civil war, Shishio was consumed with the idea of vengeance and destroying what he and the Battousai, Ruroni Kenshin (Kenshin Himura) built.
4 Foes: Gilgamesh and Kaguya Would Fight Over Who Could Claim Godliness
Kaguya is a member from the lower branch of the Otsusuki clan who later gave birth to the ninja arts by eating the fruit of the God Tree. Once she did, she became a God amongst humankind in the Naruto world by being the only person to access chakra. Eventually, she gained the moniker of The Rabbit Goddess and was mostly uncontested in power.
Gilgamesh, the king of Babylon, son of Lugalbanda, and owner of all the world's treasures, finds himself above everyone around him - even Gods. In the Fate series, he has access to every Hero's Noble Phantasm and three of his own, one of which is a world-ending weapon by virtue of sheer power. The two would likely not stand another being thinking that they could dare measure up to godhood and end up in a fight of cataclysmic proportions.
3 Allies: Junko and Makishima Want To Alter Society To Fit Their Vision
Master manipulators who both what to change society to fit their own vision of what should be. Junko Enoshima, The Ultimate Despair, wants every human on the planet to experience despair and to revel in it. Enough so that Junko, alongside the help of a few others, managed to bring the world in Danganronpa to its' knees. Shogo Makishima, on the other hand, while not an "Ultimate," still wielded almost supernatural prowess in charisma and persuasion.
While Shogo did not want the collapse of humanity like Junko did, he did not shy away from the grittier and crueler options to attain what he wanted in Psycho-Pass.
2 Foes: Madara and Meruem Have Opposing Ideologies
Both are compelling individuals who don't take kindly to competition. Meruem, in his prime antagonistic ways, was a pompous chimera ant who was gifted with great strength. Because of his upbringing and the Queen's goal to create the perfect child, he was ferocious and showed no regrets in killing humans or ants - some of which he ate after he killed.
While intrinsically strong in their own right, the two are fundamentally different in their ideologies in those surrounding them. They would probably butt heads sooner rather than later simply because Meruem considered humans to be lesser than himself before meeting Komugi.
1 Allies: Both Orochimaru and Naraku Will Stop At Nothing To Achieve Their Goals
Orochimaru, the famous rogue ninja from the Leaf village in Naruto, and Naraku, the demonic megalomaniac spider from Inuyasha, would likely be a dangerous pair to come up against. Not only do they both take the form of the biggest fear-inducing vertebrate, a snake in Orochimaru's case, and invertebrates, a spider in relation to Naraku, but they are both famously power-hungry, dangerously cunning, and will stop at nothing in their journey to get stronger.
Just the thought of those two being best buds would send understandable shivers down Naruto's and Inuyasha's spines.