Nightmare King Grimm is nearly perfect

This is part 3/4 of a series where I'll go over four major Hollow Knight bosses and their design. These four are considered some of the hardest in the game, and I want to go over them because I want to express how much I love them, but also why I don't like them.

Major spoilers for Hollow Knight, of course.

And yes, I'm doing a second one today. I'll also release the Absolute Radiance one today or early tomorrow. The only reason I only did Pure Vessel yesterday is because I needed to set up the grading rubric.

Pure Vessel/Sisters of Battle/Nightmare King Grimm/Absolute Radiance

To cover what I'm grading these bosses on...

Rubric
A (6-8 points) B (3-5 points) C (0-2 points) F (-3 points)
Telegraphing Attacks are incredibly well-telegraphed in advance. Attacks will catch you off-guard if you're not paying attention, but they're not hard to react to if you're paying attention. Attacks can seem unfair at times, catching you off-guard, even if you're paying attention, but are generally fair. Attacks are constantly coming at you with no clear or immediate indication that they will be, but are still not completely unfair. Attacks have essentially no telegraphing.
Randomness Attacks have little to no RNG involved in them. Where there is RNG, it is used fairly, and you can still predict what's going to happen and/or react to it in time. Attacks have some form of unfair RNG, making a death to sheer unluckiness possible. Attacks are mostly RNG-focused and/or are so hard to react to in time that an unlucky death is common. Attacks are a complete gamble. You might get hit, you might not. It's still possible to react in time, but often not.
Downtime The fight is fast-paced, but still allows for enough breaks to heal during it. The fight has inconsistent amounts of downtime. Sometimes there's enough, sometimes there's too little, sometimes there's too much. The fight either has too little downtime or too much downtime, making it either unfair or too easy. The fight either allows no breathing room or unlimited breathing room, even to those who don't have the fight memorised.
Ambiance The song and arena match the fight perfectly, with the song being something unique, and the arena being amazing to look at. There are also little details that elevate the fight even further, like sounds and effects. The song and arena are possibly not that good of a fit. There is also a lack of smaller details. The song and arena are unoriginal and unfitting. They are not good, even on their own. Team Cherry and Christopher Larkin are good, I don't think this tier could ever be pulled on them for ambiance.
Fun A very fun fight that can be done hundreds of times in different ways without boredom. A somewhat fun fight that you might return to when you're bored. A fight you never go out of your way to redo. The fights you dread in the Pantheons.

Now, we're doing the vessel of the Nightmare's Heart, a puppet forced to dance and die and live forever, the master of a troupe travelling the world, collecting the flames of dying kingdoms... the Nightmare King Grimm.

Final scores:

Telegraphing: A+ (8 points)

Randomness: A (7 points)

Downtime: A (7 points)

Ambiance: A+ (8 points)

Fun: A+ (8 points)

Total score: 38 points (7.6 average, low A+)

Breakdowns
Telegraphing

A+. All the attacks are telegraphed well in advance, giving you a tight window to react, but not an unfair one.

Randomness

A. There's a bit of randomness involved in the Cloak Spikes and Pufferfish, but they're sightreadable, and you can easily react to them.

Downtime

A. This fight is a dance. Going out of order means you mess up the dance. Trying to catch a break will result in punishment easily. It's slightly annoying, so I can't give it the full A+, but it's very well balanced, as there are moments where you can get a small break.

Ambiance

I mean... the theme is the best song in the game, hands down. I will take no arguments. A shame we don't hear it in the Pantheon of Hallownest. The arena is lacking in Godhome, but looking past it at the original arena... Yeah, it's great. All the troupe members in the audience, with their bright, fiery robes, and the patchwork design of the arena itself are great. And the Nightmare's Heart, too! The slow, audible beating of it, slowly getting faster as the fight continues, opening its eyes when it senses its vessel weakening... Probably one of the best-designed themes and arenas in the game.

Fun

I love trying to kick Grimm's ass in different ways. It's such a fun fight, with a tight gameplay loop that just makes it such a fun fight. It's probably the most fun I've gotten out of a game this year.

Hot take: Nightmare King Grimm does not have the best soundtrack in the game. This is such a hot take it has been blurred in a spoiler.

What could be better?
Abysmal take btw

wellllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll
Path of Pain fits the occaision

GIVE DOWNTIME A+ WHAT ARE YOU TALKING ABOUT
THE FOCUS WINDOWS ARE MASTERFUL AND WELL LAID OUT

But I kept dying :(