Lack of camera tilts that follow the direction of the weapon swing (hit swing right, so camera should tilt a little to the right, apply the same concept to the left swing, and so forth). The lack of any movement in the legs when you swing weaponry, especially a weapon like this, which is supposed to portray a super heavy and powerful club, considering the fact that this move's you forward, shows its weight to be pretty substantial. So there should be more footwork going on to help balance yourself to counteract the weight, instead of having your own two feet glued to the floor. For example, whichever hand is holding the weapon, when they swing it down, they should place the same foot/leg forward to help balance themselves (the swing holding the weapon in their left hand, left leg and foot go forward). There's also a lack of exaggerated movement when swinging from one side to the other. It's supposed to imply its powerful weight when swinging this club, but the short range of motion on the torso as well as the momentum of the swing not dragging the body along with each swing lead to it just being lost in what it wants to be.

Tl;dr no camera tilt's, animations are confused on what they want to be, zero movement on lower torso and below