Kimetsu no Yaiba has creative visuals, quirky style and simple premise that works very effectively. The hashiras are literally the coolest guys ever. However, my main issue is that the pacing and villains of totally blow.

Demon Slayer has really weird pacing decisions - the fights stretch on like 30 chapters and the in-between ark pauses are barely there. In other shounen shows writers use pauses and long arks to explore contextual tangents, build up tension, create drama, and rise stakes. That way they create an illusion of a journey and make the reader more involved to the story. Unfortunately Demon Slayer does not do any of that particularly well and the consequences show. Everything our characters do comes out like an unearned heist sequence without any impact to the story at all. The only thing that seemingly matters is who dies but I did not feel involved with any of the characters at all.

I really did not care whether any of the characters will live or not. Sure most are cool, however, they are also static to a fault. The badass design and tragic backstory are certainly there but where are the aspirations, the character, the drama? I feel like the hashiras are just some npcs with programmed responses, present only for Tanjiro (the boringest default soy boy character ever) to interact with. Admittedly, Zenitsu and Inosuke have some non-completely forced drama, but it was too weakly resolved to count. Good characters certainly don't lack style, but they do lack substance.

The writing of the villains, however, sucks pee pee. They are stuck in this limbo zone of inconsistency between a tragic backstory, goodness at heart, and the fact that they have eaten half of the population of Japan. While we, readers are meant to empathise, the villains are subjected to the stupidest most awkward character development template:
> I am not bad at all, but I live in a society
> have to protect someone excuse
> *dies *gets vampirized
> ok, now I am over-the top evil. I want power and revenge
> *gets fucking decapitated
> Tanjiro holds hand and reads last will, feels bad man
> omg, I made a mistake, I am good actually
> Tanjiro, thanks for teaching me this cheap-ass brain-dead moral lesson
> proceeds to suck Tanjiro off and dies for real

Demon Slayer has no sense of drama and everything it does is cut short. No character has any genuine development and resolution. Boring, meaningless fights are stretched far too long, while in-between moments (with training and character development) are either basic-Tanjiro-level-cringe-worthy or unexplored at all. I really hate to have to do this, but I think Kimetsu no Yaiba lacks fillers and thus shounen substance. Nevertheless, the form is unparalleled - the style of Meiji (or smt) Japan, interesting magic system, creative fight visuals, cool backstories and character design. 5/10