I believe this diff should have a general nerf. Currently this diff has a similar density to Inner Oni, and the difficulty gap between Muzu and Oni is also quite large, making the difficulty increase a bit unbalanced between the diffs.
A possible solution to this would be to decrease the amount of triplets a bit and turn some quintuplets into triplets, as well as leaving a few more 1/1 breaks in some less intense parts of the map. Here are some examples of what could be done:
00:20:611 → 00:39:140 - As this section has a very repetitive rhythm and is not yet at the peak of intensity, you could take the opportunity and delete some notes to reduce the density a bit and still add a bit more variation to the map. You could delete the following notes, for example: 00:21:125 - 00:21:346 - 00:22:523 - 00:24:581 - 00:24:655 - 00:26:861 - 00:27:008 - 00:27:228 - 00:27:890 - 00:28:111 - 00:29:581. Well, these are just a few examples, to quote them all here would make the mod unnecessarily long. But the idea would be something like this, the general decrease in density.
The same goes for kiai and the section after it, which is much denser than Muzu and relatively similar to Inner, for example 01:20:317 → 01:25:023. You could reduce the number of triplets and quintuplets in these sections, as it can be a bit tiring for players of this level, given the higher bpm.