Sylph.Kwate said:
In my experience Mind Blast is the most potent, but doesn't last very long (20, 30sec max). Reactor Cool paralyze consistently and often upon mob hitting you. I haven't had too much luck with Subzero smash at all. But just test them out and decide for yourself. MND and MACC plays a factor in how potent your paralyze will be.
Macc doesn't affect potency, ever. iirc MND doesn't affect Sub-Zero Smash para potency, not sure on the others.