Endbringers. Yes.
I have a number of problems with them, actually. The numbers waved around are simply insane, even in the context of the story. I have a strong suspicion they were pulled out of somewhere rather random because they sounded nice...
If we go from the article on the wiki, an Endbringer's torso consists of a layered material of approximately 200 layers in total, each one doubling the hardness, or toughness, or strength (which are all different) of the one before. This means the core is 2^200, or 1.61e60 times any or all of these than the outer skin. This is a VERY big number.
Now, the problem is compounded by the common description of them stating that the
density goes up by the same factor.
I find this hard to believe.
As an example, let's model the Endbringer as a bar with a cross-sectional area of 1cm square and a length of 2 meters. We have two hundred layers, each one twice as dense/hard/tough/strong as the previous one. Each layer is therefore 1 cubic centimetre, making it easy to calculate. Note that this is a tiny fraction of the actual Endbringer. The outer layer is stated to be roughly equivalent in properties to aluminum alloy. Let's say it's a really good aerospace one, such as 7075-T651. This has a density of 2.81 g/cc.
Thus, the first layer (1cm cube) has a mass of 2.81g. The next one is double that, giving 5.62g. And so on.
What does the final 1 cubic centimeter mass?
2.81*1.61e60 grams, or 4.515e57 kilograms.
This is rather a lot.
To put it into perspective, a standard solar mass, the figure you use to work out how big galaxies are, among
other very big things, is 1.98855e30 kilograms. The Andromeda galaxy, which is our nearest large extragalactic neighbour, has an estimated mass of 1.5e12 solar masses. This gives it a mass of 2.98e42 kilograms, give or take.
4.515e57/2.98e42 is 1.515e15. So that one cubic centimeter of Endbringer core would have a mass equaling that of one and a half
quadrillion galaxies the size of Andromeda. The most recent estimate of the total number of galaxies in the universe is two trillion...
So one cc of Endbringer core has the mass of 757.5 universes. Neglecting all the other layers, which are
still stupidly massive until you get pretty close to the outside. I can't be bothered to calculate it to any greater level than that, but the point is that an Endbringer doesn't, based on the common theory, mass as much as a neutron star, or even a galaxy as I've seen in some places. It would mass as much as thousands of entire
universes!
Feel free to check my calculations, it's quite possible I've made a mistake, but even if I was many orders of magnitude out, it would still be completely preposterous.
Even if we ignore the density issue and simply take the wiki entry as correct, saying that the physical properties of the Endbringer layers
other than density increase at that rate, it's still ridiculous. Less so, but close enough to magic as makes no difference.
If the mass thing is real, the Endbringers are unbeatable, by any normal meaning of the word. You could never remove enough mass from them for them to even notice. What happens to the mass you do manage to remove? Does it revert to normal density, or more normal densities? If so your planet, or solar system, goes away.
If the theory that they store most of their mass in other dimensions and bring it back to fill in any damage, as Scion is supposed to do, is correct they're still unbeatable. They have thousands of universes worth of mass to use, Earth Bet only has one to fill with bits of Endbringer. They'll run out of places to
put the fragments long before the Endbringer runs out of fragments
Sure, they're not working to their full potential, we know that, but considering them something that could be damaged at all bearing in mind the above would require them to be underutilizing their abilities so much it's just down at the noise floor. If Eidolon was able, at his peak and in theory, to solo an Endbringer, that means he was able to wipe out a universe or more. If the Entities can
give away powers that overwhelming, they're more than capable of staving off entropy and the entire thing is a waste of time.
