Roronoa Zoro is famous for his numerous powerful techniques in swords from one of the most famous manga and anime series, One Piece, by the famous manga author Eiichiro Oda. Among these, the Flying Dragon Blaze turns out to be one of the most dangerous attacks. This technique is called "Hiryu: Kaen", literally "Flying Dragon Flame/Blaze" in Japanese.
Flying Dragon Blaze is a kind of Flying Slash Attack, a group of skills that can spread one's cutting abilities into far reaches. Zoro introduced this technique as an extremely powerful form of the Flying Slash Attack, showing his growth and mastery over his swordsmanship. This attack is very noteworthy in that it comes from Zoro in One Sword Style, which he could channel immensely in power through a single blade.
In the Flying Dragon Blaze, he generates his power in one of his swords to build up a strong slash that would not just cut the target upon contact but incinerate it with flames. With the incorporation of the fire element into this ultra-powerful cutting force, the attack becomes very destructive. By combining the abilities of slashing and burning, this attack can cut down a huge number of enemies successfully, especially those weak against fire-attack abilities.
When this technique is used, Zoro's sword becomes sheathed in blue flames; the view is that of a Flying Dragon Blaze. The azure blaze enhances the beauty of the attack but gives meaning to the intensity of the heat and power that the strike holds. The blue color of the flames could be telling of an extremely high temperature, which again would reflect on the potency of the technique.
This has to be noted to the readers, however, that even though Flying Dragon Blaze will turn out to be a lethal attack, it is not any form of CoC technique. According to many One Piece fans, it is slightly similar to the Ashura technique of Zoro, which is assumed to be not quite the perfect application of Conqueror's Haki. While the Flying Dragon Blaze can cause damage to an extremely high extent, it is speculated to be less scarring compared to Ashura since the latter is related to advanced Haki abilities.
The Flying Dragon Blaze has become iconic enough to appear on official One Piece merchandise. For example, a collectible figure of Zoro casting the technique has been made with special effect parts for the blue flame blade and an Onigashima platform base. This merchandising thus represents the popularity of this technique with fans and the worth it holds within the One Piece storyline.
In the character development of Zoro, the Flying Dragon Blaze will represent one more step in his efforts to become the greatest swordsman in the world. It simply shows his ingenuity and adaptability in his swordsmanship, as he can add elemental attributes to his cutting techniques. This progress in abilities fits with the general theme of growth and betterment throughout the One Piece series.
Flying Dragon Blaze has been used in every form of media in One Piece from the manga to the anime, even video games; it easily is considered, due to its multi-platform use, to be one of Zoro's signature moves alongside other renowned techniques like the Three Thousand Worlds and Oni Giri.