The world of Vinland Saga has several powerful characters but none match up to Thors, who fans saw at the very beginning of the story. Thors ended up dying a very early death, however, he was a true warrior and forced to be reckoned with.
It is quite clear that even the strongest of warriors in the story of Vinland Saga couldn't match up to him. That said, while he certainly is not impossible to defeat, he can be challenged and given a good fight. And, there are very few characters in Vinland Saga capable of doing so.
6 Thorgil
Thorgil is a character that fans were introduced to in the Ketil Farm arc. He is the first son of Ketil and the older brother of Olmar. He has a massive build and, as expected of someone like him, he enjoys a good fight.
He is driven by his thirst for battle at times and, his nature is such that he scorns his family for being too peaceful at times. Thorgil is extremely powerful and while he's certainly not the strongest that the fans have seen in the series, he can perhaps entertain Thors for a little while before eventually being defeated by him.
5 Askeladd
Askeladd is an extremely important character in Vinland Saga. Introduced to the fans at the very beginning, his strength was always exemplary. Askeladd trained Thorfinn quite a bit while he grew up and he even fought against Thors in an intriguing battle.
While he was no match for Thors in terms of strength, he certainly used his wit extremely well. It goes without saying that he is capable enough of challenging Thors, as has been seen in the story already. He's even known to be capable of defeating people who are stronger than him by reading them like a book and taking advantage of the weakest spots.
4 Snake
Snake is another intriguing character that the fans were introduced to during the Ketil Farm arc. He is a Danish warrior who was employed by Ketil on his farm and, quite unlike the other characters that fans were introduced to in this story arc, Snake was always known to be a man of reason. He had a big heart and even helped out Thorfinn on quite a few occasions.
However, having a big heart certainly does not mean that he wasn't strong. Snake is a powerful warrior and his strength is known to be greater than that of Askeladd. At the same time, he also possesses tremendous speed that can match Thorfinn's very own. So far, out of all the characters that Thorfinn has fought, Snake has the highest speed. Fans already saw Askeladd put up a great fight against Thors. Given that Snake has more strength and speed, he can certainly do better.
3 Garm
Also known as the Hellhound, Garm is a unique character who plays a major role in the Eastern Expedition arc of Vinland Saga. He loves to fight and is incredibly dangerous to take on in battle for anyone. Even as a child, he was skilled enough to kill nearly anyone and that says a lot about his fighting prowess.
In fact, he is even known to be a match for Thorkell, which is nothing short of staggering. In his fight against Thorfinn, he manages to take the upper hand on more than one occasion, which says a lot about him. Garm is one of the strongest characters in Vinland Saga and he would certainly give Thors a run for his money, although beating him is a different question altogether.
2 Thorfinn
Thorfinn has developed into an extremely powerful warrior over the years. Although he started his journey as a bloodlusted hound looking for opportunities to kill Askeladd, he later realized what it meant to be a true warrior and acknowledge the fact that he had no true enemies. Thorfinn chose not to fight for the vast majority of his life, however, when push comes to shove, he can defend himself extremely well.
Just like his father, can fight without killing and that is where true strength lies. He can easily match the likes of Thorkell in battle. What's more, just like Askeladd, he can take advantage of his opponent's weaknesses and beat them even when they are overwhelming him, as was the case during his fight against Garm. Undoubtedly, Thorfinn is a true warrior.
1 Thorkell
Thorkell is a monstrously powerful fighter and very few can actually match up to him. If there is a character who can go toe to toe with Thors, it is him. He is tremendously powerful and very few can actually manage to hold their own against him. Dubbed to be the strongest in the world, Thorkell can easily perform superhuman feats and even wipe out armies on his own.
While Thorkell might not be able to defeat Thors, he can certainly push him to his limits. He has a great love for combat and has refined his skills over the years consistently. He is easily among the strongest characters in Vinland Saga and can certainly challenge Thors to a great fight.