The final villain of an anime is usually the one that's the most built-up, often being the main antagonist that the heroes have trained hard and struggled to face. Sometimes these villains are kept a mystery, hidden in shadow, and only whispered about in passing. Other times these villains can come out of nowhere, at the very last second, and some are even introduced very early on.
Some of these villains introduced early are meant to be a twist, others are more up close and personal, either way, one thing's for certain: it's that these final villains don't take long to make themselves known.
10 Satan Appears To Rin By Possessing Others (Blue Exorcist)
In Blue Exorcist, Satan is the king of demons, the ruler of the world known as Gehenna, and the father of Rin and Yukio Okumura. While interpretations of Satan vary between the anime and manga, he is still the ultimate evil and doesn't take long to introduce himself in both versions.
Possessing Shiro Fujimoto, Rin uses his demonic powers for the first time and faces Satan head-on. Sadly, Fujimoto dies in the process, beginning Rin's mission to exact vengeance on Satan for killing his surrogate father and become an exorcist.
9 Prime Minister Honest Manipulates The Empire As Early As Episode 3 (Akame Ga Kill!)
While many final anime villains are fighters, there are those whose strength lies in their ability to manipulate things. For Akame Ga Kill!'s Prime Minister Honest, he manipulates the child emperor into ruling the empire his way, allowing the corrupt and powerful to remain at the top and gleefully torturing anyone whenever he feels like it.
While he isn't the type to get involved in the fight himself, he was the one behind everything the empire did as well as the one directing Esdeath and the Jaegers. He can be seen taking advantage of the young emperor's naivete and stuffing his face with food as early as the very third episode.
8 Izanami Was Secretly The Gas Station Attendant The Whole Time (Persona 4: The Animation)
While Izanami isn't directly responsible for the Midnight Channel killings, she does have a hand in it and gets the ball rolling for all of Persona 4's main players, both in the game as well as the anime. The most surprising part is that Izanami had been hiding in plain sight from the very beginning of the story as an average gas station attendant.
On top of awakening Persona abilities, Izanami is also responsible for spreading the rumors of the Midnight Channel too. Eventually, Yu Narukami and his friends figure it all out, and Izanami reveals her true form in the Investigation Team's intense final battle.
7 Dio Brando, The Final Villain Of Two Separate Parts (JoJo's Bizarre Adventure)
Dio Brando is JoJo's most popular antagonist, and he wastes no time proving what a malicious person he is from the moment he introduces himself in the very first episode of the series. At first, he's fine just tormenting Jonathan and trying to seize the Joestar fortune, but as the story goes on, Dio's sights get set higher as he becomes a vampire and later a Stand User.
While Dio's influence and legacy can be felt through a large portion of the JoJo's franchise, he was also the main antagonist and final villain of two separate parts of the series, Phantom Blood and Stardust Crusaders.
6 Vicious Makes His Intimidating Presence Known In Episode 5 (Cowboy Bebop)
A member of the Red Dragon crime syndicate and Spike Spiegal's former partner, Vicious' fighting skill and demeanor are exactly as his name would imply. Cynical and seemingly only driven by anger and vengeance, Vicious attempts to kill Spike after trying to take Julia and leave the syndicate.
While he may be mysterious and quiet, Vicious doesn't take long to appear in Cowboy Bebop, appearing in the fifth episode and facing down his old friend Spike in a fight he barely survives. In the series finale, after he takes over the Red Dragon Syndicate, he and Spike finally settle the score.
5 The Major Is Seen In The Shadows Very Early On (Hellsing: Ultimate)
Millennium, a military group of Nazi vampires, is the kind of organization that only a mad man like the Major could've ever come up with. In love with the very concept of war, the Major's persistence and obsession with violence spanned far past the end of World War II, allowing him to become a cyborg to see his madness through to the modern-day.
The Major quickly becomes the Hellsing Organization's true nemesis and eventually lays waste to London. While it takes until the second Hellsing: Ultimate OVA before he's seen in full, the Major is seen in shadows in the first OVA too.
4 Kyubey's Deception Starts From The Very Beginning (Puella Magi Madoka Magica)
While he may look like an adorable little mascot character that would appear in any anime, Kyubey is undisputedly the main antagonist of Madoka Magica. Appearing in the very beginning of the story, Kyubey offers to make a contract with Madoka and others to grant their wishes if they become Magical Girls. However, this is all just deception for Kyubey's true goal.
As one of the "Incubators," Kyubey puts the young girls' souls into a gem to convert the power from their transformations and battles into energy to keep the universe going. The result was a never-ending cycle of Magical Girls being made to fight Witches, only to become Witches themselves, something Kyubey has zero empathy or remorse for.
3 Muzan Kubutsushi Is Mentioned Early And Revealed By Episode 7 (Demon Slayer: Kimetsu No Yaiba)
While it takes a little bit before the audience or Tanjiro meets Muzan Kubutsushi, the Demon King's influence can be felt from the very first episode of Demon Slayer. As the one responsible for killing almost all of Tanjiro's family and turning Nezuko into a demon, putting an end to Muzan becomes one of Tanjiro's main goals.
Muzan Kubutsushi is mentioned multiple times early on, and as a result, his presence can be felt even before his first appearance. Officially, Muzan appears partially in the sixth episode and in full during the seventh. It didn't take long for him to show how terrifying he could really be either.
2 The Seeds Of Johan Liebert Were Planted From The First Episode (Monster)
Monster's Johan Liebert is a disturbing level of evil. The main antagonist of the series, Johan is a cruel, malicious, and nihilistic serial killer who loves to cause chaos and suffering just for the sake of doing so. The saddest part is, all of his actions in the series could've been avoided.
In the very first episode, Dr. Kenzo Tenma has to choose between saving the life of a young Johan or Mayor Roedecker. Not able to let the young boy die, Tenma chooses to save Johan and inadvertently allows him to go on to commit his many atrocities from then on.
1 Light Yagami Is Both The Protagonist And The Antagonist (Death Note)
They say "the road to hell is paved with good intentions," and one can definitely infer that from Light Yagami's initial plans for the Death Note. After discovering the notebook, Light decides to use it to punish the guilty and make a world free of criminals. Despite that, it's not too long before it all goes to his head, and he begins killing whoever gets in his way, declaring himself the "god of the new world."
Light is one of those special cases where he is both the protagonist and antagonist, becoming more ruthless and arrogant as Death Note progresses, and as such, he's of course seen from the very first episode.