Neo Catharsis

lol it's super hard to bracket this, just try hitting it straight

It's not something that should be required at level 21 to handle the last part with brackets... but if you get used to brackets, the stepping is manageable and the rest is very straightforward, so it feels like an upper-mid. Of course, if you play it with straight feet, it's far beyond level 21.

difficulty is subjective based on how you approach the finale

It would be good for improving your 7-note accuracy if you go for 22, but I don't think it's top-tier.

For the two sections of slightly long 16-beat half-drill in the highlight, as well as the 16-beat drill at the end, don't hit them with precise footwork. Instead, twist your body slightly to the left and use brackets. At this point, if you step too hastily, you're likely to lose gauge due to bad-slip, so you must step slower than you think. Additionally, if you want to practice bracket footwork, I recommend Mu-hon 2 D21.