Stand was annihilated but he survived.
If he just set Diavolo's death back to zero, why would King Crimson just disappear?
I literally just gave you multiple reasons why.
This is just "I disagree because its vague" which is not even relevant to this discussion since its headcanon
That isn't headcanon, that's me pointing out it's vague as ****, which was my point, there's alternatives here, do we know for sure? Hell no, he's intentionally made cryptic by the author, is it because of what you're saying? Most certainly not, is it because of this? Perhaps, but we don't know, it's relevant to the topic at hand because you want to argue about his Stand and its relation to his soul and death, if you want to do that, then yes, it's topical, because you want to argue something deliberately made vague, it's also ironic, because literally everything you've been saying falls under headcanon, do you not realize that? And it probably doesn't even matter because GER did what he did, it just works.
If what you say isn't mentioned in the manga, the guides, anything, we aren't going to use it.
Prove he can nullify abilities
There is no way you actually just asked for proof of GER's
main ability. Bruh.
As seen in the scan above he straight up says
"You will never arrive at the reality that will occur. None who stand before me shall ever do so,
no matter what ability they may wield".
GER itself says that he can neg abilities on panel.
That's without getting into the guides, it's not even just abilities, it's actions as well, and it's not even just actions and abilities, it's for the most part, almost anything, case and point, Diavolo's death, he managed to
nullify someone's death to make it so they could never experience death and he did so to such an extent that Diavolo will be forced to go through this loop of never being able to die
forever and you think it's unreasonable that GER couldn't just make it so he can't manifest King Crimson in the same breath he made it so a dude could never die? Occam's Razer lad.
But hey, here ya go
"Gold E. was accepted by the Arrow as one who had the qualifications to control it. As the main body (Giorno) controls the power of the arrow without it going out of control,
it negated all of King Crimson's abilities. He gave Diavolo a never-ending death and ended the battle."
Direct statement that even uses the word "abilities".
This should be sufficient, I'm not digging for anything extra.
Why would you assume GER just randomly has this secret ability to use causality manip to somehow make Diavolo live without a stand?
Because that's what we're told, that's what we're shown, he's only ever stated to have causality manip and his previous abilities increased exponentially.
It's only ever stated, in all media and guides that GER killed Diavolo, set his death to zero, and put him in a death loop for eternity. So that's what happened, we know he has the means to nullify and prevent abilities, and not even just abilities, but
actions too. And we know it can be a permanent automatic thing, due to the death loop itself being an automated process upon his death being negated.
And as said, who's to say he's living without a Stand? It could be nullified, he could be prevented from manifesting it, it could be numerous things, whatever it might be, it doesn't matter, at the end of the day he didn't use King Crimson, it can be explained via RTZ, and as such we won't be giving GER made up powers never documented in the source material, guide or supplementary material, because it simply isn't the case.
Harvest survived after Shigechi died for a short while,
Backpedaling, you said, and I quote, "Stand users die
instantly when their stand is gone".
It goes both ways, a Stand could survive for a good solid odd dozen seconds after his host was literally evaporated in order to fulfill a goal, it's not normal, but it happened anyway. Stand "rules" aren't really rules, they're more like guidelines, they aren't always followed. If you want an even more extreme example of the Harvest thing, DIO being able to use Jonathan's Stand literally a century after Jonathan died (And yes, it's confirmed HP#2 is Jonathan's) And in the case of Diavolo? He's not standard fair, but as said, in the end it doesn't matter why, we go by what we see or told.
Nothing about it is similar to Diavolo's scenario. Why would you randomly assume its just some other thing keeping Diavolo alive? A lot of these seem like headcanon "what if he just survives for no reason"
Trying to undermine my argument by saying "randomly assume" this or that won't work, because it's anything but, my ultimate conclusion is based strictly going off what we see and told, it's you who keeps assuming it has to be made up powers not mentioned anywhere, I'm giving you alternatives that are entirely feasible under his existing powerset to show you why you assuming it has to be this other power he doesn't have, simply won't fly or get accepted without far more proof, proof which doesn't exist mind you.
And again, I'm not assuming some "other thing" is keeping Diavolo alive, because we
know what's keeping him alive, it's RTZ - causality manipulation, don't need to assume if we're flat out told.
No reason? We explicitly know the reason why, it's because his death was set to zero, he will
never die. He can't die. It's impossible.
Diavolo had his death negated, he will thus experience the act of dying for all of time, but never actually die, the moment he would die, he's set back to zero to experience a new death. This is what happened, this is what we see, we're told this happened because GER RTZ'd his death, and that's all there is to it.
You're arguing that Diavolo shouldn't be brought back to life without King Crimson? Or that without King Crimson he should be dead? Yeah under normal circumstances that's understandable, but that's the thing, this isn't a normal circumstance, this is a
forced infinite death loop where he can't die no matter what, whether he was brought back to life regardless of King Crimson or if he would die without King Crimson, both wouldn't matter, why you ask?
Because
he can't die.
That's the whole point, he will never die, no matter what, forever, if GER negated his death so he will never die and will be instantly fine with no damage, every experience, it's not exactly out of the realm of possibility to say that King Crimson is moot, Diavolo is alive and fine because that's what RTZ did. In fact, I'm going to say that's what happened there, RTZ is capable of negating any and all damage and detrimental effects upon him each reset and he can not and will not ever die, King Crimson is a nonfactor.
tldr, dude can neg abilities, king crimson is a nonfactor and whether he's around or not wouldn't matter either way, we aren't giving him made up abilities that have never been mentioned in anything before for things that can be explained with his existing powerset so hard disagree.
I can settle on a power null via causality manip based on it being said he can straight up do that, but that's all I can agree to.