In his eyes right now, he could see the beginning of humanity
The beginning of humanity he saw did not show him the beginning of humanity in the ancient times
Instead, it shows the progress of humanity since the Fall.
Since this sword is created with the help of the energy of the world that only originated after the Fall, that is probably why it shows the rise of humanity from the Fall and not before it
he saw the rise of humanity overcoming the obstacles of monsters and magical energy.
His eyes seem to be able to see tens of thousands of stories of humans overcoming their limits and thrive in this new world.
His middle realm of Disk Formation rises until the pinnacle of the Disk Formation leveler. Arthur waves slightly the sword and the originally cloudless skies is filled with clouds which rushed for tens of thousands of kilometers to heeds his order