Great villains drive the story's conflict in a very interesting way, and since the shonen genre is typically aimed at teenage boys, audiences can expect a lot of action due to such excitement.
Typically, the best villains will have backstories that explain their past, but never excuse their evil plans throughout their respective series.
Whether it's the deeply tormented Nagato in Naruto, the boring Askeladd in Vinland Saga, or the immoral Suguru Geto in Jujutsu Kaisen, these complex shonen villains elevate the story. They're not just obstacles to the protagonist, they challenge the heroes and even the readers with their worldview. Ultimately, whether they're right or wrong, they're too dangerous to be left alone.
Here are some of the most complex, powerful, and terrifying villains in the shonen genre:
Blackbeard in One Piece
Blackbeard is a man of many contradictions. Despite having the will of D., he is a coward who fears death. Blackbeard is a dark version of Monkey D. Luffy in many ways, despite his unscrupulous nature, this villain also believes in pursuing his dreams like a hero. He also grows in power instead of staying still.
What makes him so terrifying is that there is very little information about where he came from or why he did what he did. Blackbeard went from an unknown pirate with no bounty to a powerful Yonko with an entire fleet now worth billions of bellies.
Dio Brando in JoJo's Bizarre Adventure
After being adopted by the Joestar family, this legendary anime villain later becomes their most persistent threat in the Jojo's Bizarre Adventure series. Dio is a theatrical performer with a love of extravagance, and despite his manipulative nature, he also has a deep backstory.
In particular, despite being a villain, he gave outcasts like N'Doul a place in this world, and he spared the mother of his illegitimate child, Giorno Giovanna.
Meruem in Hunter × Hunter
Meruem is one of the strongest Nen users in Hunter x Hunter. Meruem is almost unrivaled in strength, durability, and speed. At the start of the series, he is a complete psychopath and has no regard for human life in general. However, that all changes when he meets his rival Komugi, a blind man and a master Gungi player that he could never beat.
Meruem realizes that raw power isn't everything when there's always someone better at something. His character development allows him to become more humane, and even his art style reflects this. When he first appears, Meruem is drawn with sharp lines, but then softens over time. In the end, he dies with great dignity, in the warm arms of his beloved Komugi.
Suguru Geto in Jujutsu Kaisen 0
Suguru Geto and Satoru Gojo were originally best friends, talented wizards, and excellent students at Jujutsu High School. Unfortunately, Geto was driven into a state of angry despair by human society, after suffering psychological trauma when he failed to save his friend Riko Amanai from an assassination attempt.
After some more events, Geto declares his goal to eradicate normal humans from this world because he is disgusted by their actions. Despite this, Geto still retains some humanity. During his final confrontation with Gojo in Jujutsu Kaisen 0, the two still share a brotherly bond between them.
Sosuke Aizen in Bleach
Aizen's true motives are not as clear as many other complex shounen villains. He is an extremely powerful Shinigami with plans to overthrow the Soul King, replacing the Soul King to recreate his own world in his own way. In the series, Aizen is so powerful, he desperately wants someone to push him to his limits, which is why he deliberately lets Ichigo Kurosaki evolve into his strongest form to fight him.
When the final Bleach villain is defeated and sealed, Ichigo can't help but think that Aizen let it happen on purpose.
Light Yagami in Death Note
Light Yagami is a popular high school student with perfect grades, but despite his name, there is a darkness hidden within him. The moment he finds a mysterious notebook, gaining the supernatural abilities of a Shinigami, he is completely corrupted.
Light can write the name of anyone he wants to kill in the notebook, and that person will die instantly. And so Light decides to be the harbinger of justice for the world. Like most complex shonen villains, his goal seems admirable in a certain way. With a brand new alias, Kira just wants to rid the world of criminals.
However, as the series progresses, he gradually loses his mind after the police are sent to investigate his crimes. He then becomes a self-proclaimed vigilante who is no more ruthless than all of his victims. Despite his intelligence, Light's tragic downfall is the result of his own arrogance.