I like the reincarnation ending, even though I've forgotten like half the people. ... Kimetsu no Yaiba is a nice work, but, it probably peaked at the Fire Pillar's death. I get the impression that the author was going to try and centralize every arc around a pillar after that, but for whatever reason, decided to abandon that tack after the turban dude. It became a little... muddy, sloppy, after that. People started getting red swords and this and that, and it felt like she was just trying to reach the finish line in one piece. Well, it's tough, I'm sure, to maintain a certain level of creativity week after week.
Still, I have to say, it's a great piece of work for that first half or so. I'd definitely recommend this one for the shounen genre fan.