Re: "Reducing the density of his fist"
Diamond's density is about 3.5gm/cm3.
Human flesh's density is about 1.08gm/cm3.
So, diamond is much denser than human flesh so the dialog should say, "increasing the density of his fist."
So, we have an apparent error. I suggest a workaround.
Vision was actually at a high density than diamond so that he would stay low in the water, but moving that mass at speed is very difficult. So, he decreased his density to increase the velocity of his punch. After all, the energy in the punch is defined by E=m * velocity squared. Thus, doubling the speed, quadruples the energy.
You can mail me my No-Prize.
