Let's say there is a character who can survive a nuclear explosion of 25 kilotons of TNT. Does this mean that as long as there is no energy equal or greater than what 25 kt of TNT generates, this character cannot be harmed? (25 kt of TNT is equal to 1.046 * 10^14 J) What if a character was hit by a combat knife thrown at him at 1 m/s? That's not too bad, is it? It's only 1 m/s with a mass of 0.32 kg. What harm could that do? It's not as bad as getting hit by a sedan traveling the same speed. Did you know the femur is stronger than concrete? Perhaps the idea of durability itself isn't so concrete after all, and yet plenty of message boards including FactPile assumes it is. We tend to get so wrapped up on how much energy this produces or how much energy that produces that we go so far to compare it to TNT, which is faulty, by the way. Let me provide an example. Lightning generates 1.5 billion joules (GJ). This is equal to 358.51 kg. of TNT. 50 kg. alone can do this, however. I doubt lightning would do the same in spite of its energy being 717.02% times what you see in the video. You'd sooner die by that alone than by lightning, which only 10% of those struck actually die. This may have to do with indirect strikes.
Why would someone who is caught in a nuclear explosion be unable to survive an explosive of lesser magnitudes as a stick of dynamite? I suspect it's because the two are entirely different and because a stick of dynamite is directly next to that person. Nuclear explosions don't use TNT from what I'm aware of, they're only compared to TNT equivalence because both are bombs. That's right, TNT equivalence should only be used to quantify the energy released in explosions, not anything else. Nuclear explosions generate a fireball, which is located at the epicenter. Along with it is a shock front, which does the majority of the damage. There's also thermal radiation and ionization radiation. As the explosion travels, the energy dissipates, so you're likely to survive if you're farther away from the explosion. The fireball alone makes up 40 to 50% of the energy. Another factor is if the explosion is in the air or on the ground. The latter is more dangerous.
What about a sedan hitting you at 1 m/s? Sure, it's only hitting you with 2.3 metric tons, whereas the knife is hitting you with 0.32 kg. The difference, however, is that the latter is sharper. If we assumed that the knife had a point of 1 mm^2, then that would be 320 pascals. A sedan would produce more pressure, but most of this pressure would be lost because the entire front isn't hitting the person, whereas the entire tip of the knife is. As for the femur, while it may be stronger than concrete, it only takes the correct angle to hit the bone in order to fracture it. Durability isn't all that it seems to be. It isn't all that easy to determine compared to a character's strength or speed. And yet, we all treat it as if it is. There are different types of durability, and the sooner we understand these different types, the better. Sure, one could boast about Kain's alleged durability against pressure, but that doesn't mean anything against those who can generate heat, or cold, or electricity.
Characters with elastic durability are better suited against blunt objects, depending how how elastic their body allows them to stretch, but not sharp objects. Those who can form their bodies into metal may do well against heat and cold for a time, but they are a perfect conductor for electricity and at times, corrosion. It should be so obvious, but it isn't. A character's body is hard? So what? Glass is harder than steel, but it's brittle. The more you have one thing, the less you have of another. I ask all FactPilers to no longer accept the notion that just because a character withstood this or that, that this should be enough to no longer consider any other moment in a character's history. There are more factors to durability, all we need to do now is consider them.