unfortunately, its a reference to the dark knight job from earlier final fantasy games. Given SE wanted to double down on these references, thats why we had the great animation of dark passenger cut in favour of that weird one cecil uses which does not translate well to 3d

contrary to popular belief though, greatswords arent as heavy as people think they are and the second hand is used for control rather than strength. However the majority of the greatswords drk's use as per asian aesthetics are comically long.

The blade still does move fast because of physics. Its just the animations and sounds, or at least the ones we used to use, had more weight added to them eg shadowskin was a genuine block method, delirium 1.0 has the animation pause in order to not slam the ground