This ending feels very rushed and forced.
Ever since the final "fight" began.
Yaiba is a solid series but the ending just... how everything was executed is something I cant get behind & sometimes the ending makes or breaks a series for me.
I mean if you loved this series and its ending then by all means enjoy it but the ball was dropped hard in this final fight overall. Which is a shame because this final arc started off so strong.
I think i see what you're thinking and understand, although i still think this series had a very good finale regardless of the issues with the fight.
As for what hindered the final fight, to me, it's the time skipping due to it being an hour long fight, and the spammed nature of Muzan's bladestorm. Every prior fight made it clear that every blow and strike mattered and had the chance of fatality. It was clear from the get go with Upper Moon One that they had to put their all into every blow to have a chance. This was not really the case for the finale. I would have been fine with it if Muzan found himself unable to land a single effective strike the moment 5 pillars started fighting at once, but their strategy didn't seem powerful enough to last for an hour. They kept getting injuries even over the course of minutes and suffered near-death incidents that made it feel like they were the ones on the ropes, not him. It made it hard to believe the plausibility of the hour long stalling. If there had been a little more time investment in showing that they had fully adapted to his bladestorm strategy and could keep him busy without risk of death, it would be fine, but they didn't.
EX:Just have Muzan use that AOE lightning attack he used towards the end early on, but fail to actually cause any serious damage. Juave them all jump away from it in time. Then show them repeatedly blocking and parrying his bladestorm or dodging it as necessary without serious issue. Then i would be able to seriously believe they are stalling him out and that he's the one in real trouble with danger of losing. It felt like their competence level was very easily fluctuating. AKA, right at the end, he suddenly one shot all of them at once which just didn't make any sense. It would've been better if tanjirou had just shown up while they were still stalling him out. Defeating him ended up being a group effort anyways, not some dramatic final finishing move by tanjirou, so there wasn't much reason not to have them stay relevant. Or Koyoharu could've just had Tanjirou's fully activated Breath of the Sun intensify the sun marks they got and knock them out unintentionally if he wanted tanjirou to 1v1 at the end.
They also could have had the fight only be a few minutes long and end due to Tanjirou's Breath of the Sun 13th form, not the sun itself, but i see why the sunlight death was chosen. It just felt like the fight was nowhere near as good as the upper moon battles.
Probably, the best way to do it would have been to have Tanjirou kill him at night in a group battle vs Muzan that only lasted a few minutes at most. Here's the huge plot hole:There is no reason why Muzan and the Upper Moons couldn't have just attacked at 1AM in the morning or even earlier. If he had done that, they would have had to stall him out for 6 hours or more, not approximately 1. That means their survival was basically due to plot induced stupidity on muzan's part. Either that, or literally have Tanjirou stall the guy out the whole night in a one on one fight after every other pillar is dead and just be nearly as broken as Yorichi apparently was. Those are the only two serious logical outcomes IMO.
That plot hole kind of just breaks this whole infinity fortress arc for me consistency wise as much as i like the narrative of the story so far. Now I know that Muzan would have won easily if he had thought about it even a little and given himself more than 1 hour. That is really sad for me because the story was just that close to being completely perfect.
that isn’t life threatening at all! And mitsuri just got cut on her face and cheek. I know everyone was saying she lost her arms, but that was never confirmed and we never actually seen her lose them so I don’t believe it, it’s all speculation... so why are they dead 
like wtf
