I liked the game more when everything could be explained using the laws of physics...
But it is true that it has become more difficult lately, because if it wasn't an error on the part of the author, we are leaving the OP power level and heading more towards ridiculous power level. And as I said, if their durability was really at the level that some people here are trying to claim it is, then to kill lvl 5, you would probably need destroy a good chunk of our planet.
You are assuming that
A. all surviveability comes from durability
B. that durability can only be overcome by brute force.
both assumptions are wrong.
They are not converting magic energy into mundane kinetic energy that packs more energy than 100 nukes. that would be preposterous.
Rather, their attacks remain magical, and its magical properties overcome the magical defenses.
With magic nullifying magic non explosively.
Also, destroying the planet is entirely on the table.
But is prevented by the higher ups which include time travellers, precogs, and masters of space (which include pocket dimensions, banishment, etc).
One of the top aces is a teleporter girl, who is fighting the mutated ring thing.
During their fight you are bleeding out between different alt dimensions and eventually a pocket world is destroyed.
And she can teleport you into deep space if you become too much trouble.
If a fight looks like it will crack the earth then they will teleport that monster to a black hole instead.
Laws of physics only work when you know what they are, and the game's premise is that there are eldritch monsters of unknown origin, probably from some other universe, who obey unknown principles of physics or reality doing things beyond uor comprehension. What do you want the author to do, give you a detailed scientific breakdown for everything?
That guy is wrong. but your reply to him is also wrong.
The exact details of the laws of physics are irrelevant.
If "giant monster A" requires "more than 100 nukes to the face" to kill and then goku flies over and kamehamehas it with "powerlevel of more than 100 nukes" then his blast will be doing immense collateral damage like 100 nukes blowing up.
This is not "physics", it is simply the actions described in the story.
BUT, that guy is you are replying to is wrong. Not because of your "physics don't matter" thing.
but because nowhere in the story does it say that they are tossing kamehamehas with more than 100 nukes worth of explosion. He is incorrectly assuming that level 5s are converting their magical attacks into kinetic energy or thermal energy attack that hit with a force greater than 100 nukes.