Guts is the main protagonist of Berserk. He has been hounding Griffith for what he did to the Band of Hawk and Casca. Guts never expected Griffith to do such a thing. He felt betrayed by his friend and thus, he began his journey to defeat Griffith.
Guts was already a top-notch mercenary before he joined Band of Hawk. His skills only improved with time. Currently, Guts is able to fight against apostles. His sword is Dragonslayer, which can slice through humans like butter.
10 BETTER: RORONOA ZORO
Roronoa Zoro is one of the most well-known characters within the anime community. He is one of the strongest fighters within the crew. Zoro uses a unique three-sword style, which is his own creation. However, Zoro is not limited to using three swords; he can use one sword style as well as two-sword style. Zoro's technique is a perfect blend of power and technique. It won't be an exaggeration to say that seeing Zoro fight is very enjoyable.
9 WORSE: SASUKE UCHIHA
If the list would be based purely on power then Sasuke would wipe out everyone else. Sasuke is a swordsman without a doubt. Throughout the series, the fans have seen Sasuke fight several opponents using his sword. While using his sword, Sasuke uses his Sharingan and Rinnegan as well. Not many characters can cope up with Sasuke's attacks due to his variation. Despite, his amazing speed and power, Sasuke lacks in one department, which is finesse. He doesn't have a proper sword fighting style.
8 BETTER: KENSHIN HIMURA
The list would be incomplete without the inclusion of Kenshin. Kenshin is the main character of Rurouni Kenshin. It wouldn't be wrong to call him a genius.
Kenshin was carrying out missions for the government when he was still a teenager. Kenshin has both style and speed, which makes for an excellent combination.
7 WORSE: SAKATA GINTOKI
Sakata Gintoki is the main protagonist of Gintama. He made a name for himself with his skills. Gintoki was given the name of "White Yaksha," which translates to White Demon. He also fought some super strong opponents throughout his lifetime. However, his skills cannot be compared to Guts. Guts' skills with the Dragon Slayer are extraordinary. Even in closed space, Guts is able to outmaneuver his agile opponents.
6 BETTER: JIN
Next up on the list is Jin from Samurai Champloo. Jin and Mugen have very different styles. Jin used orthodox fighting styles while Mugen had no fixed style. Jin's orthodox style is much more pleasing to see. Jin also had good speed to match his swordplay. He is a very good swordsman and throughout the series, he fights numerous strong opponents.
5 WORSE: KAMADOU TANJIRO
Tanjiro is the main character of Demon Slayer. After seeing his sister being turned into a demon, Tanjiro made up his mind that he would turn her back to normal.
Tanjiro is a good swordsman and he has shown the fans that he can take of opponents with his sword. Tanjiro's attacks have enough power and speed to obliterate demons.
4 BETTER: DRACULE MIHAWK
Dracule Mihawk is from One Piece. He is the strongest swordsman in the series. Mihawk is the perfect swordsman as he combines power, speed, and precision in his sword style. Purely from a swordsman's point of view, Mihawk's skill is far great than Guts'. Even in terms of pure power, Guts cannot defeat someone like Mihawk who sliced a galleon, or an iceberg. He might put up a good fight if he uses the Berserker armor, but Mihawk is simply superior with his sword skills.
3 WORSE: FLASHY FLASH
Flashy Flash is one of the S-Rank heroes from One Punch Man. Flashy Flash's main strength is his astounding speed. He has fought against several monsters, which is a testament to his level of skill. However, Flash's technique is mainly dependent on his speed. He usually blitzes his opponents and gives them no opportunity to react. As we know in a fight that striking first is a very big advantage. Flash makes sure that he the first hit in, which leaves his opponents weak.
2 BETTER: KILLER B
Killer B is arguably the most unorthodox swordsman on the list. He was adopted by the Third Raikage when he was still a little boy. Killer B is capable of using a single sword as well as multiple swords at once. Killer B fought against Sasuke and he absolutely demolished Sasuke. Sasuke was unable to keep up with the sheer speed and technique of Killer B. B can also use tailed beast chakra to increase the strength and power of his attacks.
1 WORSE: ASKELADD
Askeladd is one of the main characters in Vinland Saga. He is the person responsible for the killing of Thors. Askeladd relied on his wit to get him out of the most troublesome situations, but his skill with the sword cannot be overlooked. He was a capable fighter, but he had his limits. Askeladd could only try to fight Guts, but Guts' superior skills would hand him an easy victory.