"Tbh, this just means he wasn't worthy of fate, not the arrow..." But what does the arrow find "worthiness" from, the entire narrative exclaims that "those who are blessed shall be worthy of the arrow" or "those who destined are worthy of the arrow", so isn't the arrows entire thing tied to "fate" and reason?

"If Diavolo was under the right circumstances, he probably could have changed fate and gotten KCR but oh well..." If I'm not mistaken the entire point of Epitaph and and the TE is to skip to where the fated outcome occurs, pretty much all of Epitaph's predictions were already going to happen before Diavolo tries to "change" it after the 10 seconds, the only time this closes scenario when this isn't the case is during the GER logic that happens due to it already being destined differently before he even "predicts" it.

^^ok but that's different

Notice how Arakibmade it so instead of Diavolp just not being worthy, he just wasn't stabbed at all

Implying that if Diavolo was stabbed, he would have evolved. Hence why Araki had to make it so Diavolo wasn't stabbed at all.

The arrow can deem you worthy but fate can make it so you don't get the arrow at all to prevent the evolution.

Like if Diavolo wasn't evil, he could have gotten KCR.

"If I'm not mistaken the entire point of Epitaph and and the TE is to skip to where the fated outcome occurs"

No, he skips past them without Diavolo being part of it. So if Diavolo had the arrow, then "whoops, time erase" and uses the arrow inside of erased time, nothing stops him...

Have we ever really seen the method to how the arrow "rejects" a stand user? What if the arrow phasing through his stand WAS him being rejected? Plus if he wasn't evil, he wouldn't really have any set up or reason to seek the arrow in the first place.

"No, he skips past them without Diavolo being part of it. So if Diavolo had the arrow, then "whoops, time erase" and uses the arrow inside of erased time, nothing stops him..." So he noclips out of things via his free movement within his ability? (So what if he was specifically snapped away from reality by the infinity gauntlet mid time-skip? Would he be erased from reality or would he survive it?)

^^no, the arrow going through him was because Bruno was bullying CR, reversing his effects.

Idrc what Diavolo would be doing if he wasn't evil. Point is, he didn't get shit cause he's evil, not cause he wasn't worthy...

"So he noclips out of things via his free movement within his ability?"

As long as they weren't connecting with him before TE, yes

"So what if he was specifically snapped away from reality by the infinity gauntlet mid time-skip? Would he be erased from reality or would he survive it?"

He would survive it because during that snap, he wasn't part of the world.

And if that's the case then Dio doesn't to exist to others who can't move within it when he uses his ability? Then if every time-related stand has that {excluding anyone besides the user) thing, then how tf does the rules worlk for MiH, BTD and Mandom in terms of time-ability rules and existence logic?!

TS is a different case. He stops time. He's still part of reality, all he did was stop the flow of time.

Diavolo outright erases time and space, setting him apart from reality.