Simple thing here is that you need to show feats of his regeneration. Best you can say is that upon his incarceration Central had no means to kill him. Mugetsu was the best they had and it only destroyed half his body leaving another half there from which to regenerate.
And I might add that Gin's bankai destroys you on the cellular level, but Aizen regenerated back.
While true that means nothing when over 2 thirds of your body is still there in which to regenerate from. Had his whole body have been destroyed then you could give him regeneration on that level, yet as you said it only destroyed a few vital organs in that area so still not enough to survive complete obliteration.
The limits of his regeneration were shown when he was hit with Mugetsu, and until he shows something above that, that is his limit. Low to mid city level durability from which he can regenerate. Anything
But on mere physical damage on the level of mountain+ at best, I don't see it.
Its a good thing his blasts are well above mountain level then.
But really, you cant claim that without any evidence, at best he is scaled to the best attack Central 46 had at the time of his incaceration which is one of 2 things, Mugetsu or Ennetsu Jikogu. Evidently Yamamoto didnt try to kill him with that else he would be dead so the only other attack as Mugetsu which did enough damage to screw his regeneration up (Was only able to regenerate his real body and not his amped one) and cause him to lose hope and regress in power.
His Reigan had enough force to obliterate islands worth of rock in the Makai, I see no reason why Aizen, who had half his body destroyed by a much, much weaker attack will fair any different in this case. If you can't show durability and regeneration feats of Aizen in which he can survive such an attack then he won't survive it. Plain and simple.
Despite his greater raw power I doubt Yusuke can destroy you on the cellular level.
At that level Yusukes Reigan will splatter him across the ground well beyond the shown limits of his regen and durability.
Getting most of your upper body destroyed on a cellular level which houses most vital organs and getting cut in half are no small feats
In both cases a good portion of his body remained, his regeneration beyond this is spectulative and without feats it wont hold up to your claims.
the fact is that Aizen could not be killed. And it's not a no limits fallacy. With statements of his immortality and multiple feats supporting this I don't see it that way.
By Soul Society standards anyway. It is a No Limits Fallacy to claim his regen has limits higher than what is shown. Statements mean nothing in this case as immortality as pointed out above is a very vague term, and multiple feats? 2 feats, both of which a good portion of his body remained from which to regenerate from.
it's not a no limits fallacy to say that he couldn't survive being burst into multiple pieces
That is a no limits fallacy, and a composition fallacy. You give him regeneration above his shown limits (No Limits Fallacy, no feats to back up the claim), you claim that because he can regenrate part of his body on a celular level he can regenerate his whole body on a celular level (Composition fallacy, no feats to back up the claim), and you base all this on the fact that Central called him immortal and that he survive part of his body being disintigrated.
Besides, i don't get where this burstinga spirit gun is coming from. I haven't seen it burst someone to pieces. It's predominantly concussive force which Aizen can tank all day long.
Bursting people comes from the fact that it shatters mountains in the Makai and his punches break apart plateaus.
The Bolded, do you have any evidence to support him tanking the explosive force of a 500 gigaton blast to his chest and coming through that completely unscathed? It has enough power to shatter mountains and islands worth of Makai stone and rock with utter ease. He is getting ripped appart by the explosive force of a reigan unless you can prove differently.
It's a greater no limits fallacy to say Yusuke's spirit gun could override Aizen's immortality without seeing the upper limits. It's at least just as big an assumption.
No, we know the exact limits of his spirit gun.
His reigan is sporting the combined explosive power, force and energy of all shown quantifable attacks in Bleach combined and then some... casually. His punches are around the exact same level via shockwaves alone... casually. Aizen is going to die, there is no argument to be had here.
There is no such thing as a greater no limits fallacy in this instance.
The no limits fallacy is you giving him regenerative abilities he does not have
The composition fallacy is to claim that because part of his body was destroyed on a celular level, his whole body can be and he can still regenerate. I dont go around claiming that Kizaru can tank attacks on this level because his regen limits have not been shown, I also dont go around saying Hashirama can regen through attacks on this level because no limits have been shown for him either. why should I allow people to say Aizen can do the same?
The most plausable response here will be "No feats to prove their regen", to which I say exactly.
If you want to argue regen then I am more than happy to start saying Kizaru solo's all of bleach because they have nothing to put him down, as does Hashirama. Both have never shown limits so both have no limits at all.
The above is a no limits fallacy, which is what you are doing to Aizen here now. We go based on what is shown, not on speculation.
The burden of proof is on you to provide evidence that Aizen can survive such powerful attacks and regenerate from them. Without that we go by his best showing and dont apply fallacies to his power to try and raise him up.
Most of the attacks he "survived" left much of his body intact. Trying to say he can survive more than what was shown is a No Limits Fallacy. Even using statements he is not strong enough to surivive attacks on this level.
Dont apply a NLF to his regeneration because when I last checked Central 46 is neither omniscient nor has the raw power and hax that other verses have. They are not imformed enough to say that someone is immortal to ALL physical damage, just as people here are not informed enough to make the claim without backing it up.
Yusuke does what Central couldn't and then goes to kill the rest of Bleach for their incompetence.
Nice. tl;dr version: Assuming Aizen's regen is godly because he has shown no limits is an NLF. Yusuke being of a caliber that dwarfs all of Bleach, let alone Aizen, should easily be able to pick him off with usage of his massively hypersonic+ speed and island busting power.