If you, too, found yourself upgrading your needle in Hollow Knight: Silksong and regularly wondering if you had actually upgraded it because it didn't seem to make a bit of difference when fighting several enemies, please join me in a resounding "Ohhhh" upon discovering the enemy-specific damage multipliers that Team Cherry apparently added in for difficulty balancing.
Having religiously avoided any potential spoilers following Silksong's release, I apparently missed the initial discovery of these multipliers, which were helpfully laid out by data crunchers like Reddit user FeldrinH. Thankfully, I did catch some discussion in recent posts and videos around the Silksong community. Intrigued by hushed remarks, I went digging, and now it feels like this completed a circuit in my head. That's why some of the scaling felt so wonky as I used very soft mental arithmetic to track my needle damage.
In essence, I've now learned, Silksong uses varying scalars to determine how much of your maximum needle damage is dealt to each enemy based on the upgrade level of your needle. As you upgrade your needle, these multipliers get smaller for many enemies, meaning your needle is dealing more damage, but you are dealing less of your needle's damage per swing to these enemies.
In practice, this ensures that enemies never die too quickly. Anti-insta-kill measures, basically, letting enemies fight back a bit. It gives Team Cherry a bespoke floor for hits-to-kill to tune around without worrying about collateral damage. It also means that when you upgrade your needle, you're basically entering a new bracket of difficulty scaling. You will be stronger, but you might not notice the difference against several enemies.
The Beastfly makes for a tidy example, per FeldrinH's spreadsheet. You'll deal full damage (1.0 multiplier) to a Beastfly with each swing of your default needle, but at every upgrade past that, you'll only deal 80% (0.8 multiplier) of your maximum damage. A level three, four, or five needle will still hurt a Beastfly more than a base needle, but compared to enemies like the beefier Cloverstag, which has a 1.0 upgrade 5 multiplier, your damage will technically be reduced.
The lowest multiplier I've seen is 0.45 for a level 5 needle, which ensures that encountering this type of enemy late in the game won't totally spike the intended difficulty of the fight.
Just like Hollow Knight, upgrading your weapon in Silksong is all about break points. If an upgrade doesn't reduce the number of swings it takes to kill an enemy, perhaps in combination with other attacks like ranged weapons or poison, that upgrade doesn't really have any effect in that specific engagement. This is why bosses, with their much larger health pools that lack these fractional break points, always illustrate upgrades more clearly.
This is complicated by the varying move sets and damage values of the many different Crests that Hornet can use in Silksong. You might shave off one hit with an upgrade while using one Crest, but changing your fighting style could increase the hits-to-kill at the same upgrade level. The addition of these unique needle multipliers only complicates this further. It also explains that strange itch I had in the back of my mind after getting my needle to level four, in particular.
