I know other users already replied here, but I just want to clarify some extra stuff.
Similar shockwave feats haven’t been accepted for one other verse only, but at least four of them.
I’m not sure how does this has anything to do with Muzan’s shockwave. If they didn’t accept those feats for JJK they most likely had their reasons, which aren’t necessarily the same are you’re bringing up for Muzan's feat.
What exactly do other calculations being wrong have to do with Muzan's feat? Furthermore, the same rules apply for all the verses in the wiki, we don’t make special exceptions, and Muzan's calc simply doesn’t transgress any of these rules and follows the same structure as many other accepted and implemented calculations.
Kiriya and his sisters being harmed by the shockwave and the databook statement are pretty much enough to prove the shockwave did reach all the way to mansion.
Again, this is only your personal interpretation of a scene that has no explicit meaning. Yes, the shockwave happens, we see the dead crows, and then we see Kiriya bleeding from the attack; but that’s all there is to it. There is quite a leap from that scene alone to conclude the shockwave was transmitted through Yushiro’s BDA. The sequence might just be a transition to switch from the battlefield to the mansion, without it having anything to do with damage reflection at all. If you’re claiming the attack reflected through the talismans, then you must provide evidence to support your claim, a personal and subjective interpretation of a scene without any explicit meaning is no evidence.
The databook statement isn’t vague at all, it explicitly states that a long-ranged attack from Muzan injured Kiriya. Even if we ignore the databook, the only logical conclusion is that the shockwave extended all the way to Kiriya’s mansion, as there is no other way it could have possibly injured him; the databook simply makes the matter clearer.
The only way you could get around this is by making the underlaying assumption of the shockwave being reflected through the crows, however, you have provided no evidence to support such claim, while all the other available evidence strongly contradicts it.
"Absence of evidence is not evidence of absence". Just because no other demon hunter seemed to be hit by Muzan’s shockwave doesn’t mean that’s what actually happened. Furthermore, the energy from a shockwave dissipates over distance, and it does so “fast”, as it follows a 1/r² proportionality (r being the distance from the epicenter), and it should be remembered that Muzan tried to flee from the battlefield and ran away for quite a while, so he must have gotten away from the rest, reducing the energy from the blast they must have experienced. Even if we assume Muzan ran away for a mere 5 seconds (even though he ran during 6 full pages) at peak-human speeds, he should have gotten around 60 meters away from his initial position, effectively reducing the potency of the blast hundreds of times for those near to Muzan’s initial location when compared to the energy Obanai was hit with, as him and Tanjiro were the ones closest to the epicenter.
Do you realize that every other single instance of the crows being killed or talismans getting destroyed show absolutely no damage reflection at all? Claiming that all of these instances are an inconsistency because they directly contradict that one single occasion in which the damage was supposedly transmitted through the talismans sounds like an extremely convenient assumption…
Come on now, if every other piece of evidence shows that damage can’t reflect through Yushiro’s talismans, then the conclusion is quite straightforward: Damage simply does not transmit through the talismans.
The anime doesn’t exaggerate the feat nor does it contradicts the manga. As I said, both manga and anime show that Gyutaro’s attack caused massive destruction by destroying several buildings, with this being further reinforced in the novelization. The key point is that the anime provides a reliable way of precisely quantifying the amount of destruction while also meeting all the standards of the wiki.
- The anime was supervised by the author.
- The feat is present in both mediums (anime and manga), thus it’s not anime only.
- Both manga and anime show the attack caused massive destruction, a notion that’s also supported by the novelization; therefore there is no contradiction across different sources.
In conclusion, the calculation can be used.
The manga not providing a timeframe for the feat doesn’t mean the anime can’t be used, as there’s nothing suggesting the timeframe differs from the manga to the anime. If anything, the manga shows how Gyutaro’s attack extended several meters by the time Tengen had only managed to move around 2 meters away from Gyutaro’s body, suggesting the attack was extending fairly quickly, which is in line with the anime scene.
Once again, the anime arises no contradictions, so there is no issue with using it.