Before he was The Black Swordsmen, he was feared as the 100 Man Slayer. This happened while fighting a battle against an opposing army. Due to being separated from the rest of the Band of the Hawk and needing to defend Casca who fell ill, out of desperation, Guts solely slays 100 men. This moment shows that Guts has incredible stamina and determination. Killing 100 men all by himself demonstrates that Guts is a man that is a man that he is the best at what he does, and what he does isn't pretty. Even though he was a highly skilled and seasoned warrior, this battle tested his then limits and makes audiences and friends and foes alike to question whether or not Guts is truly human.

Even though Guts’ use of the Dragon Slayer in the first anime series is exclusively limited to the first episode, this sword is an overall contributing factor to the popularity of the Berserk brand name (some of a pun intended) as a whole. Constructed by Godo, a blacksmith who once worked for a king, he was asked to make a sword that could kill a dragon and that is what he made. Seeing that the sword was impossible to use, Godo fled the kingdom and lives as a hermit but continues to make swords for mercenaries. The sword probably paved way for Cloud’s from Final Fantasy VII from all we know. But it is incredibly big. More than 20 years later, the sword found its wielder through Guts, a man who is accustomed to wielding such heavy metal. Thanks to his freakish strength and experience, Guts handles the sword like how a geisha would handle a fan. With one swing, he can make a small company of bandits be chopped in half and slay the most fearsome of monsters.

Even though this is only briefly shown in the first episode of the old anime (and the last episode shows why he lost his arm to begin with), when in desperation, it shows that the prosthetic is not for show and it packs some heavy duty fire power. While he was wrapped around by the Baron’s snake form, he fires it point blank blowing a chunk of his face. In addition to that cannon, he has a small crossbow mounted on top just in case he needs to fight in long range conditions. Plus, in a fist fight, it would help to pack a punch.

Three years after he was brought into the Band of the Hawk, Guts develops a very close relationship with Griffith and his relationship with the army ultimately grows. If anything, the army would be nothing without Guts despite how powerful Griffith and Casca are. One day, Guts felt it was time to move on with his life and leave the Band of the Hawk. The main motivation for this is that he wanted to earn Griffith’s respect as a friend. However, Griffith still sees Guts as property and challenges him to fight for his freedom. Despite how lengthy their first fight was, after being more battle hardened while Griffith’s skills rusted while playing politics, Guts makes quick work of Griffith with one swing by destroying his sword and stopping his blade at his shoulder. Even though he could have done more damage, he chose not to since he respects him as his friend and he got what he wanted, his freedom. Little did he know that this moment would further set motion what would happen.

This is demonstrated in his first fight with Griffith who comes across as more educated and refined in his fencing style, Guts in a fantasy sense is more of a brawler. Most of his education just came from pure experience and was never taught any form or technique. He was simply taught just to kill the opponent. In his first with Griffith, Guts goes as far to throw dirt in the opponent’s eyes showing that he will do anything to win and was one of the very few people to go toe-to-toe with him despite being humiliated by having his shoulder located by a Fuji Armbar. In his debut, even though Guts carries a big sword and has the built of a professional bodybuilder, he also has incredible speed. This is demonstrated when he fights Bazuso, a feared knight. While bragging how he he's going to kill Guts, Guts doesn't bother listening and just goes right for the kill. If anything, Bazuso doesn't see him coming. Granted Guts was an early teen in this battle, but he was still bigger than boys his age and was still carrying a sword that adult men could never swing. So he is a warrior with size, speed, agility, experience, and a undying sense of determination.