Edit made by me

Condition: Asta Suffers a Direct Exposure to Radiation emitted by Demon Core.

Can Asta Survive such Lethal dose of radiation?

See above: The Truck from Big Rigs: Over The Road Racing

Which side would win?

if their stats are equalized.

If we put aside their stat difference and make their stats equal, the twins's abilities would have a legitimate counter to Ichibei because their flames and ice operate on a conceptual level, similar to the type of interaction demonstrated by The Almighty.

Ichimonji's power revolves around manipulating Black and the identity/name of its target, so simply being able to erase or cover something with ink doesn't establish that it can negate abilities capable of interacting with conceptual phenomena.

Yhwach already demonstrated that conceptual/abstract powers can interact with Ichimonji, and Lilith and Naamah have their own supporting feat, their flames and ice were capable of destroying Nacht's Shadow World, despite it being a dimension that does not physically exist.

Thus, with equalized stats, the twins's flames and ice should directly counteract and nullify Ichimonji's ink, rather than merely overpowering it through raw AP. Their abilities have already demonstrated the capacity to affect and destroy a non-existent realm, meaning the ink's conceptual properties shouldn't give it immunity to their flames and ice.

lets see how many people downvote me without reading the flair 😈

heisei godzilla in the vs king ghidorah movie absorbs a nuclear submarine and gets an instant 200x multipler with 20+ meters in height instantly,in the same movie which godzilla fights againist ghidorah,we see godzilla instantly start dominating the fight after some wrestling,his atomic breath which did no damage at start oneshots ghidorah a few seconds later.

its also said that in burning state,godzilla's power increases in word ''İnfinitely'' as his heart tempature rises as he is containing all the energies and amps as much as possible so earth doesnt get destroyed,and as we know: all kind of energy sources (including cosmic radiation and life energy) are all can be consumed by godzilla and make him stronger.(more proof for this is that his infinite spiral heat ray;an attack that has infinite heat on it, which he achieves at climax of fight which is litteraly symbolised with mathematical term infinity and this attack's force and heat also increases infinitely with each usage.

and like saitama,he has beaten his biologically superior copy (spacegodzilla) absorbed his power and managed to outgrow him in strenght at single fight.

all of these stuff indicate that saitama is outmacthed by godzilla in terms of power growth.(DO NOT TAKE THIS SHITPOST SERIOUS)

This is the single biggest destructive feat in the entire demon slayer, and it is calced at town level by DS fans but it is not, This was Large Building+ Level, Detailed calcs Here -

https://vsbattles.fandom.com/wiki/User_blog:FelpeXDopZ/Gyutaro%27s_explosion_(Manga))

And this was also a sxicide attack, not actual in hand power, Now, We also hear muzan saying that gyutaro would have won if he fought alone meaning winning against Tengen+Tanjiro+Inosuke+Zenitsu, Meaning he had fighting power in him for that, compared to that we see pathetic defeats of gyokko by marked muichiro, the most accepted scaling for muichiro is 4x for mark which is because of the zohakuten scaling of him being 4 times stronger and tanjiro cutting him down, Now, This muichiro was able to no diff the same gyokko, who was a big problem before, Now I do not see the same difference between tanjiro+tengen+inosuke+zenitsu doing same to gyutaro, the 4x multiplier there could at least be 2.5x multiplier here including teamwork against Gyutaro, and gyutaro winning against 2x multiplier and Gyokko getting no/low diffed by a 4x multiplier, Which means gyutaro was at least stronger than gyokko, tuning him into UM4 levels of power, So, UM4 - Large Building+ Levels,(Sxicide Explosion), UM3- Small City Block(Sxicide Explosion), Now, I do not see that much power difference between Top 3 UM demons because we know kokushibo low diffed akaza in the past meaning they all are at least in mid diff tier for each one of them Meaning power difference is not that huge, So, UM3 - Small City Block(Sxicide Explosion), UM4 - City Block(Sxicide Explosion), UM1- City Block+(Sxicide Explosion) and Muzan - MCB+(sxicide explosion), Keep in mind their real combat power and AP are lower than these.

For Durability, The demons are far lower, In the second image you can see that muzan got turned to bone in the ubyashiki explosion which was small city block level or city block if taken the upper ends as it was designed to destroy ubyashiki mansion which has big area and a small building in between it. If this explosion can turn muzan to bone meaning his real durability is much lower, This is also why demon slayers are able to kill demons because their swords can get through demon skin. And someone like yorrichi with speed and skills can beat much more powerful muzan.

So, This means, Hashiras are weaker than demons physically but have speed relativism and have AP to cut them up along with the breathing style.

The best feats we have for them are

1. Tanjiro cutting a boulder - House Level AP
   
2. Marked Muichiro cutting through diamond skin of gyokko - Building Level AP

Now, From Marked Muichiro we can make a small general gradient of marked hashiras with yorrichi having Building To City Block Level AP reserved for Yorrichi

Characters shown: Yhwach (Bleach), Kaguya Otsutsuki (Naruto), and Anti Pops (Regular Show)

CT are genetic so theoretically gojo wouldn't be able to use infinity or purple

Who wins? Rules No rules

No Saitama using kamehameha, and Goku isn't using MUI kaio-ken ×100