Diamonds are appreciated!
Rolling back the clock to a time when the overworld was inhabited, we find the ancient Monument Dwellers. The Brawlers were those with reckless or rough personalities. One might help in battles as a sort of berserker, but most of the time they would be paid to fight monsters in the arena. The arena could be submerged or on land, so the Brawlers needed to be both good swimmers and dextrous in footwork. Because the conduit wasn't invented until the floods, they would wear special helmets with the waterbreathing enchantment when in a submerged arena.