Flying Weapon

You know what the weakest point on a typical sword is? The wielder.

A flying weapon is a weapon capable of fighting without anyone touching it. It floats into the air, moves as if there were an invisible hand guiding it, and attacks freely. Some flying weapons will stay near a particular user, parrying attacks against them; others operate entirely on their own. Sometimes they're magical tools, or haunted weapons, or wielded telekinetically.

A flying weapon is very likely to be an Empathic Weapon, and may also be an Attack Animal (or even an Equippable Ally if it has a life of its own). Nearly always a Cool Sword. See also Attack Drone for the real-world high-tech equivilant. When it is a sword and used in large numbers, they may overlap with a Storm of Blades.

Also a valid way to summon a weapon to one's hand.

Anime and Manga

 * Orochimaru from Naruto can do this with his sword the Kusanagi.
 * In Rune Soldier Louie, a man went around pretending to be a Master Swordsman and Knight In Shining Armor, but it turned out he had a "Dancing Sword", which did all of the fighting on its own, and he just held on. When faced against another Dancing Sword, he lost his grip, leaving the swords flying around as they fought each other.

Literature

 * Xanth novel The Source of Magic. While going to a masquerade ball Bink is attacked by a flying sword sent by an unknown enemy. Luckily for him the sword is not very skilled at swordplay and he can parry its blows. He finally neutralizes it by getting it to stick itself into a gluebark tree.
 * In the Conan the Barbarian story "The Sword of Skelos", the titular weapon is a sword enchanted with the four elements which can fly around and kill people when ordered.
 * In The Wheel of Time there are several occasions where a bubble of evil causes weapons (and sometimes other objects) to start flying around trying to kill their owners.
 * The evil Black Sword in Michael Moorcock's Elric (and other) series occassionally self-propels its way to a target/victim in a manner not unlike flight. Wielded by the Hero Urlik Skasgol in Phoenix in Obsidian, the Sword celebrates its return to the hands of the Eternal Champion by leaping from Urlik's hand to take the life of a passing slave girl. Thrown off the back of a dragon in high flight by Elric, whose intention it is to lose the Sword in a deep sea several thousand feet below, Elric is later consternated to discover the Sword has flown back, under its own power, to take its accustomed place in the City Armoury. In one Elric story, the Sword flies away in a time of great danger, only to return with an uncountable number of its brothers and sisters from other dimensions - a cloud of Black Swords that make mincemeat of the enemies of Elric of Melnibone.

Live Action TV

 * In one episode of Charmed Paige's husband fights against a sword that was being telekinetically controlled by a British witch who wanted to produce magical offspring with Paige.
 * Early in Fantaghiro, the White Knight training her has her fight a flying sword, to teach her that the best defense is not, in fact, offense. The lesson is that defending yourself takes priority over attacking the enemy.

Mythology

 * In Norse Mythology, Freyr's sword can fight by itself.

Tabletop Games

 * Dungeons and Dragons
 * Module S1 Tomb of Horrors. One room had swords mounted on the walls. If any attempt was made to escape, the swords flew off the walls and attacked the escapees.
 * Dancing Swords were also a magic item available for general use in earlier editions.
 * Molidei demons have flying two-handed axes as their standard equipment.
 * Module S1 Tomb of Horrors. One room had swords mounted on the walls. If any attempt was made to escape, the swords flew off the walls and attacked the escapees.
 * The Hero-Deity Kelanen Prince of Swords in the Greyhawk setting. While wielding a normal sword, each minute of combat he can create another sword (to a maximum of nine) that flies through the air and attacks his enemies.
 * A n umber of spells create weapons that attack the caster's opponents, such as Mordenkainen's Sword and Spiritual Hammer/Weapon.
 * "Mobile" weapons in In Nomine Satanis Magna Veritas. Holy/unholy relics behave as very powerful mobile weapons that can cast spells. Both kinds count as a power.
 * Shadowrun: While it's easier to find robots that have a open weapon port there are rules for adding propulsion methods including flight to your weapons.
 * In Nomine supplement Superiors I: War & Honor. Dominic's angels can gain a Servitor Attunement called Heavenly Judgement. If they encounter someone guilty of murder or a greater crime, a luminous sword appears and attacks the guilty party.

Trading Card Games

 * Magic the Gathering has a Dancing Scimitar. The page pic, Ensouled Scimitar, is another example.

Video Games

 * Most likely Exor from Super Mario RPG. It doesn't move as much in battle due its size, but it doesn't have anyone wielding it and flies during cut scenes like the game's intro.
 * Runescape has Magic Axes, floating axes that attack on their own, as well as Possessed Pickaxes, their more mining-oriented cousin.
 * Donkey Kong Country 2: Diddy Kong's Quest: Kleever, which is a giant living cleaver. It is the boss of Crocodile Cauldron.
 * The Final Boss of Knights of the Old Republic II fights using three lightsabers at once, levitating at least two. While lightsabers are not autonomous storywise, each acts pretty much independently.
 * A common enemy in Castlevania:
 * Played straight in the Sword Companion.
 * Subverted in the Hunting Girl, Vandal Sword, and Azaghal: the swords turn out to be wielded by invisible swordsmen.
 * Mabinogi has a whole class of Flying Sword monsters.
 * In Dragons Lair there's a room where you're attacked by a flying sword. Then a flying morning star. Then a spear. The by a whole anvil
 * In the Kingdom Hearts series Sora can use the Master and Final Drive forms to cause the equipped Keyblade(s) to float alongside their user. Likewise Aqua from Birth By Sleep can do this when in her Spell Weaver command style. Xaldin from Organization XIII wields several spears in this manner as well.
 * This trope appears on occasion in the Final Fantasy series
 * Exdeath from Dissidia Final Fantasy may carry his sword in his hand but when attacking he will always move it with magic. Vaan can also do this with a Simple Staff instead.
 * Vayne Solidor, the Big Bad of Final Fantasy XII, commands several magical swords called Sephira.
 * There are monsters in Final Fantasy XIII and Final Fantasy XIII-2 that have an ability called Forge Blade which creates one of these as a new monster in the encounter. If you destroy the sword, it will create another shortly.
 * In the not-yet-released Final Fantasy Versus XIII, Noctis has a whole arsenal of weapon he wields this way.
 * Secret of Mana has two enemies that are this: The Doom Sword and the Evil Sword.
 * Irelia in League of Legends owns four of these
 * In Atelier Iris 2, the final boss uses not one, but sixteen of these things at once, resulting in some horrible combo attacks.
 * In Lufia 2 Rise of the Sinistrals you will encounter enemies called the Cursed Sword and Cursed Armor, of which the former is one of these. If you kill them, there is a chance of getting the same item as a drop.
 * In Diablo II there are haunted scimitars. These may drop a normal scimitar when defeated, or merely shatter.
 * In The Legend of Zelda Twilight Princess, there is a miniboss that seems to be one of these, but its body is actually invisible.
 * The living sword family of enemies in Tales of Symphonia are also floating swords.
 * In Drakensang 2: The River of Time, the Final Boss will always summons a threesome of floating magical swords to aid him in his battle.
 * In Neverwinter Nights, the Swords of Never guarding a tomb are supposed to be these. In fact, the designers cheated a little- you're actually fighting human warriors with 'null' character models, so only their swords are visible. To interact with them, you still need to click where the person holding the sword should be.
 * Warcraft 3: On arriving at Frostmourne's vault, the sword breaks free of its icy covering and lunges out to kill Muradin. He gets better by World of Warcraft. It doesn't show this capacity again.
 * In World of Warcraft Blood Death Knights get an ability called Dancing Rune Weapon, including the parrying bit.

Web Comics

 * In Tower of God, swordsman Hatsu dual-wields a flying sword, 'The Sword That Flies Higher Than Any', alongside a more conventionally-wielding blade.
 * The Blade of Sigmr Ch'k in Kagerou, which is implied to take different forms for different wielders. For Kano, its hilt is covered in sharp teeth, making it necessary for him to use his telekinesis to wield it.

Western Animation

 * There was an episode in the original Thunder Cats series where Mumm-ra disguised himself as King Arthur, claimed Excalibur from the Lady of the Lake, and sets out to pick a fight with Lion-o. At a point during their duel, both swords fly out of the hand of their owners and begin fighting in mid-air.
 * Quick Draw McGraw - El Kabong ran into an opponent who knew how to do this by technique, they ended standing by watching their rapiers duel for a while.
 * The magic sword in Kim Possible could fly when called like a dog. But only for and to Ron Stoppable.
 * Bugs Bunny has a singing sword in "Knighty Knight Bugs" (Freleng 1958). Not really useful for fighting, but it could carry a tune quite well....
 * In Scooby Doo Monsters Unleashed when the Black Night was introduced? His sword started fighting by itself?
 * Gargoyles: Thailog in the episode sanctuary had a rifle that could fly.