With a few exceptions, every anime hero needs a weapon. The Shinigami of Bleach are armed with Zanpakuto, Naruto characters utilize all sorts of ninjutsu, and One Piece's cast is armed with a variety of devil fruit abilities.
While weapons can range from immaterial powers to mecha to traditional arms, more than a few anime weapons have minds of their own. Sentient weapons are a fantasy staple and often symbolize a character's internal struggle or serve as individuals in their own right. These anime weapons need to be appeased, negotiated with, or cared for in order to do their jobs properly, and even then, they're likely to voice their opinions.
10 Yukine Was Once A Real Boy (Noragami)
Among the most human and collectively endearing of all sentient anime weapons are the shinki of Noragami. In the Noragami universe, gods conscript the services of dead human beings to work as their weapons. Early in the first season, Yato bonds with the departed soul of a little boy named Yukine, a spirit as restless as he is strong.
Yukine almost always appears in human form apart from when Yato uses him in battle, at which point he shapeshifts into a katana or a pair of katana. But Yukine is moody and sometimes hard to control, so he and Yato have to mature together for it to become a perfect partnership.
9 Senketsu Is The Sassiest, Deadliest School Uniform (Kill La Kill)
A weapon doesn't need to be a traditional blade to be effective, and ever the creative series Kill La Kill was especially inventive when it came to arming its protagonist. While Ryuko does wield a dangerous scissor blade, arguably her greatest weapon is her school uniform, a sentient shapeshifting creature known as Senketsu.
Typically coolheaded and logical, Senketsu proves a real asset in battle and often acts as a sort of parental figure to Ryuko. He transforms into powerful armor when satiated with blood and boasts numerous special abilities.
8 Samehada Is Hungry For Chakra (Naruto)
Caring for pets can be a difficult undertaking under the best of circumstances, but what's a villain to do when his pet is a very hungry sword? In Naruto, Akatsuki member Kisama wields a sentient sword named Samehada. Passed down for generations, Samehada is as tall as a man, scaled like a fish, and toothed like a shark.
Samehada feeds on the chakra energy of other creatures and always chooses its own master. While Samehada doesn't speak in a way most people can hear, it makes its intentions known to those who hold it, rejecting unfit wielders and making its users aware of its food preferences.
7 Saika Confuses Love With Violence (DRRR!)
Durarara!! is a series that blurs genres together with enthusiasm. So, it isn't really surprising for an urban legend and a demonic sword to appear in the backstreets of Ikebukuro.
Saika, known also as "mother," is a demonic blade that's infatuated with humanity. Unfortunately, the blade feels closest to humanity when possessing them and must cut a human to make them its host. Saika won't rest until all of humanity is under its command and speaks incessantly to those who wield it, driving most of them mad.
6 Anubis Is A Terrifying, Sentient Stand (JoJo's Bizarre Adventure)
Considering the variety and creativity on display in the Stands, or abilities, of characters in the JoJo's Bizarre Adventure canon, a demonic sword was bound to make an appearance.
A sentient, userless Stand that takes on the form of a sword that can control those who wield it, Anubis proves a tenacious opponent in Stardust Crusaders. When unsheathed, Anubis looks like the god of its namesake but looks like a sword in a scabbard otherwise. Bloodthirsty and ruthless, Anubis is a terror.
5 Migi Is Both Shinichi's Weapon And Corrupter (Parasyte)
Migi isn't strictly a weapon, but the alien parasite that invades protagonist Shinichi's body in Parasyte: The Maxim is plenty sharp when the need arises. Parasyte is a series that indulges in more body horror than most, and once Shinichi's hand becomes Migi's new host, his body gains the ability to shapeshift into all sorts of gruesome forms, blades included.
Migi is a logical monster, most often depicted as an amorphous hand with a single eye. While it starts off as an apathetic creature, gradually, Migi becomes more empathetic and even fond of their human host.
4 Ragnarok Is An Abusive Weapon (Soul Eater)
Soul Eater is one series that wouldn't exist without the central, driving concept of sentient weapons. The Death Weapon Meister Academy pairs would-be meisters with demonic weapons, the latter of which usually look much like human beings.
Maka and Soul are the anime's central wielder-weapon duo, but most of the cast takes part in similar arrangements. Notable among these is the dysfunctional relationship between Crona, a demon swordmaster, and Ragnarok, a demonic sword that's downright abusive to its wielder.
3 Derfflinger Has Some Things To Say (The Familiar Of Zero)
While a sword named "Derfflinger" might not sound especially threatening, the sentient sword showcased in The Familiar of Zero proves more useful than most. Derfflinger is capable of speech and doles out advice, but as an older sword, is prone to forgetfulness and sometimes annoys other characters.
Derfflinger can absorb spells and control the body of his wielder should they faint in battle, so the pros certainly outweigh the cons.
2 Shichika Sees Himself As A Sword (Katanagatari)
One series that subverts the sentient weapon trope is Katanagatari. The male protagonist, Shichika, is descended from a long line of martial artists who see their bodies as swords. Shichika is raised in isolation on an island far removed from other human beings. Since his youth, he's been taught that he's a sword rather than a person, and empathy is initially difficult for him.
While Shichika is an effective weapon, it takes the bulk of the series for him to learn how to be an effective, caring person as well.
1 Morgif Can Speak, Supposedly (Kyou Kara Maou!)
Few sentient swords are as fundamentally disappointing as Morgif of Kyou Kara Maou!, but perhaps the comedy fantasy series knows what it's doing. An unremarkable sword that bears a small face on its hilt that's oddly reminiscent of Ghostface of Scream fame, Morgif should be capable of speech.
However, it's revealed that Morgif is no longer what it once was, having changed after being doused in a hot spring. The most the modern sword can manage is to let loose an unhappy groan or bite an unwanted wielder.