Ending is a little disappointing. A lot of good fight sequences in earlier arcs, but this final one felt rushed. Then, Muzan's character is left empty; we never get his story and while I understand he feared death, but... so does every living person and he needs to set himself apart. Plus how did he become a demon in the first place? Is it something special to him or could others follow in his footsteps? And that final chapter, I had a hard time telling who's who. And no Tamayo?
Honestly, I feel like the ending was rushed almost like it needed to end quickly, but the anime forced it to get an actual ending.