Kirigaya Kazuto, aka, Kirito is the protagonist of the popular anime series Sword Art Online. The black swordsman has faced countless challenges within the unyielding world of SAO and has overcome these trials through sheer talent and willpower. The dual-wielding swordsman has had numerous close-encounters with the afterlife but has defied the odds over and over again to become the savior who completed the death game.
As one of the greatest heroes ever to step foot into the virtual realm, Kirito has the ability to dodge bullets and cut down enemies in a single strike. With such terrifying potential and talent, there are very few within his 'verse who can push Kirito to his utter limits.
10 Stronger: Konno Yuuki
The leader of the Sleeping Knights Guild was famous throughout the lands of Alfheim Online and had earned the nickname Zekken for winning sixty-seven consecutive duels. The Absolute Sword had taken on warriors from all across the virtual space and none could beat her and her swordsmanship.
She was renowned for using the eleven-hit original sword skill Mother's Rosario, a move that could tear apart enemy defenses in a flash. Kirito and Yukki have gone up against each other, and Yukki has proven that she indeed possesses superior swordsmanship.
9 Weaker: Suguha
Suguha, aka Leafa, is indeed one of the strongest sylphs within Alfheim Online. She possesses a variety of spells and magical attacks in her arsenal and isn't too shabby when it comes to swordsmanship. But despite these achievements, she still is nowhere near the level where she can actually pose a threat to the legendary Black Swordsman.
Kirito, with his superior reflexes and experience, would easily come out on top in a battle against Suguha, and he wouldn't even have to resort to his ace, that is, the dual-wielding.
8 Stronger: Gabriel Miller
Gabriel Miller, aka Subtilizer, is a ruthless, cold-blooded character who enjoys tormenting his opponents. His arrival in the Underworld had sent the entire human forces into complete disarray and his tactical knowledge had given his army an edge in the war.
After the death of his character Vecta, he made a second appearance as the Subtilizer and had single-handedly destroyed some of the strongest characters present in the virtual space. Kirito was up against one such character whom he couldn't have defeated alone and had to rely on everyone else supplying him with power to overcome this monster.
7 Weaker: Vassago
The former leader of the Laughing Coffin, who once went by the name of Poh, is a player who has been terrorizing Kirito since his early days in SAO. He was the one who forced Kirito to kill players and take lives and in the process managed to drop a heavy mallet of regret on Kirito's heart.
His appearance in the War of the Underworld spelled doom for the entire resistance and had a bit of an upper hand against Kirito in their much-awaited fight. But towards the end, Kirito unleashed his true power, and Vassago could do nothing but cower in the face of such unrelenting power.
6 Stronger: Bercouli Synthesis One
The leader of the Integrity Knights was one character who was respected throughout the underworld. As a legendary character, he had led the integrity knights successfully and had defended his borders for centuries. His sword The Time Piercing Sword was arguably the most overpowered sword ever to exist in the history of SAO.
His sword had the ability to slash through time and could cut a person in the future as well as in the past. His ultimate attack allowed him to slash a person's past, thus completely killing him in the present. In the face of such time-bending ability, Kirito would be unable to come out as the victor.
5 Weaker: Tsuboi Ryoutarou
Tsuboi Ryoutarou, or more commonly known as Klein, is one of Kiritos best friends, both in-game and in the real world. His banter with Kirito has always been very enjoyable and has been a fan favorite since day one.
Despite being a beginner at first, he soon became familiar with the mechanics of the game and became strong enough to hold his own against other powerful foes. Klein is still miles away from reaching Kiritos level and would stand no chance in a one on one fight against his best friend.
4 Stronger: Kyaba Akihiko
The genius creator and game master of SAO were once revered by the masses but soon became a devil for trapping thousands of lives within a virtual space. His in-game alias, Heathcliff, founded the strongest guild in the game and he was also the owner of the unique skill Holy Sword.
He and Kirito are both unique skill wielders, but the latter being the game master has the undeniable edge when it comes to battle. Even after turning off his AI assist, he still proved to be way too strong and Kirito towards the end needed a massive plot armor to save his own life.
3 Weaker: Fanatio Synthesis Two
The deputy leader of the Integrity Knights has long held the title of the second-best swordsman in the underworld. Her weapon, the Heaven Piercing Sword is a divine weapon with massive destructive capabilities. The sword has the ability to fire high-intensity light rays that can burn down anything it comes in contact with.
Her swordsmanship is extremely lethal and has slain might beasts. But despite possessing such a divine weapon and power, Fanatio did fall in a battle against Kirito, with Kirito seemingly not exerting the full extent of his powers.
2 Stronger: Asuna
The Lightning Flash has earned her nickname for her extremely fast rapier that can shred opponents in a single instance. She is one of the most talented wielders of the blade in the history of SAO and has always stood at the front lines to protect her loved ones. Her relationship with Kirito has melted hearts and to this day stands as a testament to the power of love.
Asuna was later given Mother's Rosario by Yuuki, allowing her to carry out the lethal combo that had once defeated Kirito. Although this would be an extremely close battle, Kirito would probably let his guard down due to the history he shares with Asuna and this might just give her the edge to come out as the victor.
1 Weaker: Silica
Ayano Keiko, aka, Silica is a dagger-wielding beast tamer who was one of the survivors of SAO. She was first seen seeking helo from Kirito to save her beast and since has journeyed with Kirito and his gang through various virtual realms.
Her knowledge as a beast tamer is next to none and she is well known across the lands as one of the best beast tamers to exist. Her beasts, being strong in their own rights, would stand no chance against Kirito and her swordsmanship is just lackluster when compared to Kiritos dual wielding, giving the latter an easy victory.