This is one of the best Ideas for a devil fruit I've seen yet! I'm just trying to think of some weaknesses for it. I don't think just mere fire can affect it TOO drastically, and I don't understand how someone with superhuman strength is a "weakness" to something that's a liquid. My best guess for a weakness would be Fleet Admiral Akainu's Magma-Magma Fruit. It could damage a Liquid nitrogen person, but then again, the sheer cold of liquid nitrogen could harden magma into obsidian. So basically, if one overwhelmed the other, that person would beat the other. The Cryo-Cryo Fruit is, in short, a very very dangerous devil fruit with few weaknesses.