Dual Blades

Dual Blades (二刀流) is a Unique Skill in Sword Art Online. The player with the fastest reaction time gains this skill. It was awarded to Kirito for being judged to have the fastest reaction speed in the game, and is meant to be given to the person who will stand against the final boss. In addition, it also has its own set of Sword Skills unique to it. Kirito wields Dark Repulser and Elucidator for this strongest sword set.

Techniques
Kirito estimates there are slightly more than 20 techniques to the Dual Blades skill. In the series, Kirito has been seen using the following:
 * Double Circular: 2-hit combo
 * Starburst Stream: 16-hit combo
 * The Eclipse: 27-hit combo

Timing Conditions

 * Attack Speed Bonus: 1.80x
 * Weapon Defense Bonus: 1.50x
 * Cooldown Time Bonus: 1.20x

Sword Art Online
In Sword Art Online, Kirito was able to use his Dual Blades skill very efficiently. The first time he used his unique skill was during a major boss raid while trying to save several members from the Aincrad Liberation Force. He later used his skill again while performing a duel against Heathcliff, which he lost the battle. He used his swords during a second raid against the seventy-fifth floor boss, and finally, he used the 27-hit Dual Blades Sword Skill «The Eclipse» against the revealed creator of «Sword Art Online», Kayaba Akihiko, and he was defeated.

ALfheim Online
While Dual Blades skill is not available in ALO, players are able to wield two weapons like the Dual Blades from SAO but does not have a system-generated skill assist or is it influenced by the Dual Blades Skill stats. Since ALO's skill mechanics is based on the actual person's skill in using his/her weapons, the player has to actually learn and be proficient in using the said skill. Lyfa stated that there were some players who tried to use Dual Blades in ALO, but it needed a lot of practice and experience to be actually effective in combat, as it is also the same in the real world, as there were only a few who could dual wield kendo swords very effectively. Kirito was able to use dual blades in ALO mainly because of his experiences from using Dual Blades in SAO, although his Dual Blades Skill stats was copied from SAO to ALO, ALO did not have the Dual Blades Skill, so Kirito had to rely on his previous experience to be able to effectively dual-wield two swords in ALO.