A growing debate over the years among Berserk readers has always been whether or not the use of Guts' sword is, for lack of a better word, impractical. Granted, any sword that matches the sheer size and stature of Guts' Dragon Slayer is bound to be effective in battle, there is no doubt about that. However, that is assuming that anyone in real life could actually handle something the size and stature of The Dragon Slayer.
Even for a man as strong and hefty as Guts, holding up a sword this big wouldn't just be difficult, it'd be next to impossible. Regardless of how big or small a person is, it is unlikely they could even try to pick up Guts' signature weapon of choice without pulling some sort of hernia. Then again, Berserk is a manga so it's not too hard for readers to suspend disbelief without having to imagine real-life logistics.
However, cosplayer James Deeley of All or Nothing Cosplay continues to make the impossible seem possible in his cosplay as Guts. Not only does he pull off being The Black Swordsman with a miraculous believability, but he also makes it look just as believable to see a man hold up Berserk's 12 inch-wide, 400+ lb Apostle slaying sword. Deeley has worn the cosplay before, but it is in his most recent cosplay that showcases the agility that an ordinary-sized man is capable of producing while helming a beyond ordinary weapon.
Perhaps the ridiculous nature of the sword compared to the man holding it is completely intentional. Seeing how Kentaro Miura's 14th volume of Berserk sees Godot openly acknowledge that the sword is too big for someone to pick up to the point of being unusable, hence why he was shocked to see Guts use it to slay an Apostle with ease. It is an image that readers can be utterly impressed by, but question the logistics of it when placed in a real-world setting. Maybe that's why audiences to this day have yet to see some kind of live-action adaptation of Berserk because the idea of a man holding such a large sword is too ludicrous to suspend disbelief for when placed in a real-world setting.
James Deeley challenges that notion often challenged by readers by making it look far too easy, not to mention looking good doing it. Maybe there is hope for a live-action Berserk one day after all.
Source: James Deeley on Instagram