Spy x Family is a hit shonen action anime series focusing on the found family of the Forger household. This charming new family came together when the Westalis spy Twilight/Loid Forger adopted the telepathic child Anya and married the assassin lady Yor Briar to form a fake family for the sake of his mission. Even by shonen standards, this is one wacky household.
Anya Forger is the real star of the show, an adorable, hilarious, and brave little girl who's packing some serious telepathic powers. She may be terrible at studying and act bratty at times, but Anya has figured out creative uses of her unique abilities to aid her new mother and father, not to mention herself. But as talented as she may be, Anya is no match for other gifted anime children, toddlers, and even infants who have strength beyond their years.
10 Eri Has A Scarily Advanced Quirk (My Hero Academia)
The charming character Eri can be directly compared to Anya Forger, with them being unusually talented young girls who were once experimented upon until they were rescued and gained some guardians in their lives, Mirio Togata and Loid Forger respectively. These anime kids would get along wonderfully if they ever met.
Between them, though, Eri is by far the stronger anime child. She can't easily control her Rewind Quirk, but there's no denying her awesome ability to reverse someone to an earlier state, a power that the villainous Overhaul weaponized for quite some time. Eri also used her formidable power to heal Izuku while he use One For All at 100%.
9 Filo Is A Combat-Ready Bird (The Rising Of The Shield Hero)
Filo the filolial is another anime kid who should remind fans of Anya Forger, and vice versa. Filo is a cheerful little girl with supernatural powers that make her stronger than most of the adults around her, but unlike Anya and Eri, she's not actually human. Instead, filolials like her can simply assume a human form.
Filo, when she morphs into her true bird form, is a heavy hitter. She can use wind-based magic, deliver devastating attacks with her talons and tirelessly pull a wagon for hours across the kingdom of Melromarc. Even without telepathy and spy gear, Filo is definitely stronger than Anya is.
8 Mannish Boy Is Like Freddy Krueger (JoJo's Bizarre Adventure)
Most Stand users range from adolescents like Giorno Giovanna to elders such as Joseph Joestar or Gray Fly, but an exception is the baby boy known as Mannish Boy. He is at most a year old, making him one of the youngest anime characters of all time. And he's far from defenseless.
Mannish Boy is a Stardust Crusaders villain, meaning he's packing a Stand. His Stand, Death 13, looks like a scythe-wielding judge/jester that can assassinate people in their dreams, where the victim cannot use their own Stands. He's far deadlier than Anya or even Eri or Filo.
7 Toph Beifong Is The #1 Earthbender (Avatar: The Last Airbender)
Toph Beifong is the world's strongest Earthbender as well as the first-ever metalbender. Toph was born blind, but she did learn earthbending from the badger-moles, so she could sense other objects and people with vibrations in the earth or rocky surfaces. She is also a terrifically powerful fighter with her bending.
Toph may be just 12 years old, but she had what it took to fight alongside Aang, Katara, and the others to defeat the Fire Nation and end the Hundred-Year War at last. Toph even slightly borrows Anya's telepathy by using her bending to sense when people are lying, and she would soon identify Loid Forger as a total liar.
6 Killua Is Deadly At Age 12 (Hunter X Hunter)
Killua Zoldyck is a popular secondary character in Hunter x Hunter, and he might have partially inspired the design of Naruto's Sasuke Uchiha. It can definitely be said that this boy is far stronger than Anya Forger, even if he has no telepathic abilities to his name.
Unlike Anya, Killua was trained for combat, being born into a family of assassins. He can move quicker than the eye can follow to deliver instant death, and he can also use his Nen to perform devastating lightning attacks. He could slaughter the entire cast of Spy x Family if he wanted to, all as a 6th grader.
5 Thorfinn Karlsefni Learned Combat At An Early Age (Vinland Saga)
For the most part, the seinen antihero Thorfinn Karlsefni was seen in action as a 17-year-old, but he was a powerful fighter even before then. At age 6, this poor boy witnessed the death of his father, Thors, and he instantly grew bitter and hateful toward Askeladd, the one responsible for all this.
Thorfinn soon became Askeladd's unofficial foster son and learned the ways of combat from the Viking commander. Thorfinn was never strong enough to best Askeladd in combat, but he was certainly fast and dangerous with his twin knives, and it can be presumed that even before adolescence, he was far deadlier than Anya Forger.
4 Wendy Marvell Uses Wind Magic (Fairy Tail)
Wendy Marvell is one of the Fairy Tail guild's youngest members, but she is not to be underestimated, even if she is self-deprecating most of the time. Wendy is the sky dragon slayer, putting her in the same category as Natsu and Gajeel. And, of course, she has an Exceed friend name Carla by her side.
Wendy joined the Fairy Tail guild at age 12, and she only grew stronger and stronger. She can use powerful wind-based magic and inhale oxygen to power up her magic, and eventually, she used Dragon Force to become a devastating warrior in melee combat. She even took on a demon book of Zeref.
3 Lieutenant Yachiru Kusajishi Is Deceptively Powerful (Bleach)
Most Soul Reapers range from young adults to elders, but an exception is the youthful Yachiru Kusajishi, the second-in-command of squad 11. She is Captain Kenpachi Zaraki's unofficial foster daughter, and even though she rarely fights, Yachiru can easily defend herself in combat if Kenpachi isn't around.
Yachiru can use a zanpakuto with impressive skill, and she can also use her shikai, Sanpo Kenju, to summon two creatures to fight for her. This shikai can deliver heavy damage to the opponent with attacks that are nearly impossible to avoid, and Anya Forger would be greatly impressed if she saw this. Anya has never held a sword in her life.
2 Sasuke Uchiha Was Already Deadly At Age 12 (Naruto)
In the world of Naruto, 12 -year-old children are deemed old enough to undertake official ninja missions, and that's the age at which they graduate from the academy. Naruto, Sasuke, and Sakura all graduated at that age, but Sasuke was far stronger than either of them in Team 7.
Sasuke isn't quite on Itachi's level, but at the time, he was still ranked among anime's most powerful children, a 12-year-old boy who can use advanced taijutsu, ninjutsu, and weapons to easily defeat his foes during a mission. No wonder Naruto chose him as his first true rival.
1 Lucy/Nyu Is A Mighty Diclonius (Elfen Lied)
Lucy, also known as Nyu, is no ordinary kid. In fact, she is not even human. She is a Diclonius, a humanoid being with horns on her head and the power of vectors, or invisible arms. She can use those vectors to grab, block, or attack anything near her, and she is capable of killing. Not even bullets can get past those vectors.
Lucy/Nyu may be powerful, but her strength brings her no happiness at all. In fact, it alienates her from society and drove her to kill people as revenge for being rejected. She is living evidence that natural talent can be more of a curse than a gift for some anime kids.