Genryūsai Shigekuni Yamamoto's (Bleach) Zanka no Tachi is a blade of compressed flames of such intensity it can incinerate everything without a trace or even a spark.
Genryūsai Shigekuni Yamamoto (Bleach) using Hadō 96: Ittō Kasō to create a giant sword tip of intense flames, though requiring his arm as a catalyst.
Bazz-B (Bleach) using his Burning Finger 4 to cover his hand with a flame-like sword, causing massive incendiary damage upon slashing down on his target.
Shuren (Bleach) compressing flames into a solid blade, which can clash against an actual solid sword.
Rin Okamura (Blue Exorcist) unsheathes his sword, Kurikara, which then releases the sealed blue flame of Satan within it.
Rei Ōgami (Code:Breaker) creating twin blades out of hot and cold hellfire of Mammon, allowing him to create a vortex to draw in his targets.
Hotstreak (DC Comics) using his fire-manipulating powers to form a sword out of fire.
Princess Mandie (Fairly Odd Parents) wielding a flame sword of hot plasma.
Recca Hanabishi (Flame of Recca) using Saiha to create a blade out of flames which has strength dependent on its temperature.
Raziel (Legacy of Kain) wielding the Fire Reaver.
Sasuke Uchiha (Naruto) forming the Sword of Kagutsuchi out of the inextinguishable black flames of Amaterasu, igniting anything it pierces.
Itachi Uchiha (Naruto) using Fire Release: Phoenix Sage Flower Nail Crimson to imbue shuriken with flames, launching fiery bladed projectiles.
Atsui (Naruto) using Cloud-Style Flame Beheading to coat his sword with flames, which creates massive waves of fire with his swings.
Seimei (Naruto) wielding a sword that generates vast amounts of fire that can be manipulated.
Mui (Naruto) using Heavenly Prison Fire Sword to solidify flames into a sword, which causes anyone he stabs to erupt ablaze.
Quartum (Negima! Magister Negi Magi) using the ultimate fire blade, the Divine Sword of Blazing Conflagration, against Negi Springfield.
Kamakiri (One Piece) using a Burn Blade that ignites compressed gas into a flaming blade, capable of slicing through a giant tree with ease.
Portgas D. Ace (One Piece) using Shinka: Shiranui to fire off spears of fire that can pierce through a person with ease.
Fossa (One Piece) igniting his sword by coating it with flammable substance, and igniting it with his cigar.
Kin'emon (One Piece) using Karyu Issen to slash through Vegapunk's dragon, causing it to burn upon slicing.
Caesar Clown (One Piece) concentrating oxygen with a lighter to form Blue Sword, generating oxidized flames that can burn down his entire lab with one swing.
Kuyō (Rosario + Vampire: Season II) coating his sword and himself with his Flame Emperor's Battle Suit, creating a blade of intense foxfire.
Makoto Shishio (Rurouni Kenshin) using the serrate edge of his Mugenjin to ignite the human oil it has soaked up, and the resulting flames into a vortex for his Final Secret Sword: Kaguzuchi.
Shana (Shana of the Burning Eyes) using her Great Blade of Crimson to coat her blade with flames.
Madoka Mawari's (Tenjho Tenge) S.A.B.B. Gas Blades are acetylene and oxygen compressed with ignition, burning at 4000°C.
Starjun (Toriko) wielding his flaming sword Burner Knife, which creates massive waves of flames that can cut deep and long with a single swing.
Hiei (Yu Yu Hakusho) forming his Sword of The Darkness Flame that can cut through even Kuro Momotaro's armored hide.
Gamma Akutabi (Zombiepowder.) using Karinzanjutsu to coat his sword with the Black Flames of Bloodlust.
Surtr (Marvel) a Fire Giant with it's mighty fire sword.
Flame Princess (Adventure Time) uses her flame sword.