His strength is like a Monster Hunter named npc, lol. The guys who solo elder dragons in one shot.
@sketches
Part of it is leverage. That's why he had to stab the sword in the boulder, instead of just trying to lift it. Even if you're strong, if you can't balance an object you can't lift it properly.
Also, we saw the water he made into rain react in a pattern not consistent with brute force. It stuck together into a stream, but also swirled and curved in ways it can't 'normally'. Its very probable that the weapons still have some of the energy of the monster they're made from in them. That sword could be from a powerful water type behemoth, for example.
Then there's also the fact that he thought there would be other Hunters, as well. Against normal humans, his strength is overpowered. But against another hunter in similar gear, they equal out. So he wanted his 'best' gear just in case he had actual opposition.
@jimmyclear
Hunters are people, too. There are good ones, neutral ones, evil ones, etc. Not sure why being a Hunter would stop someone from being willing to slaughter. What if they BECAME a Hunter due to bloody urges? Or gained the urges due to being a Hunter? They are still human, after all.