Your threshold was low enough that if creating lava was not mentioned in the LN, then we dismiss the lava created in the anime
You are either misconstruing me or completely unable to grasp what I mean at any point.
I never said this, and the fact you imply so sounds like a terrible strawman. I simply said that if anything in the LN happened that would render the VS feat inapplicable, then I would be all for discarding it. Whether it be the feat being much smaller, Karna being completely immune to the heat and therefore tanking none of it, etc. You know, like
literally every other similar feat where the source material and the adaptation differs? Conversely, if the feat was even bigger, I'd be all up for calcing it and potentially using it for scaling.
A more powerful version "barely killed him"? Let's see... Saber
kills him the first time, mangling his extremities some. And then kills him
a second time so hard that he loses all limbs. Did I mention his
third death where he is left looking like Charcoal? This certainly doesn't contradict the fact that Heracles' creates such powerful resistances that they work on NPs, right? Meaning his resistance would nullify stuff that can one-shot him, right? It would nullify something stronger than Mana Burst, but not stop the weaker Mana Burst, because that is somehow logical, right?
If in your world this is not a contradiction, you must live in fairyland.
The multiverse stuff is just meaningless trash. Multiverses don't suddenly make adaptations be as valid as the source material, and don't make contradictions suddenly be ignored. But I really don't care about telling you that right now, because if you think Saber Alter being able to kill Berserker with the same ability, multiple times, is not a contradiction, then your mind is made up and I genuinely don't care enough to try and change it.