How Hollow Knight taught me to work smarter, not harder
It took me almost exactly two hours to defeat Lost Kin today.
The first time you fight him as the "Broken Vessel", he has a very predictable pattern that just requires you to be patient, evade his attacks, punish him when he's open, and keep grinding until he goes down. Once I figured out the pattern, it took me maybe three minutes or so to defeat him on probably the fifth try.
It turns out that the second time you fight him, unless you can somehow react as fast as my cats, and evade not only his attacks (which are faster, happen more frequently, and leave less room open for punishment), and also avoid jumping into the Infected Balloons all the time, then you're still not going to make it, because he takes an almost endless beating, and is going to wear you out until you make a mistake, which is when he really punishes you, because when you take damage and get nervous, so the simple fact that he keeps zig-zagging around the space, makes it hard for you to figure out where to run away to.
One other thing that I noticed, is that he likes to push you into a corner, because when you are against the wall, then you can't reach the Infected Balloons to take them out, and that makes it extra hard to dodge him when he attacks. Maybe about an hour in I began to try to stay in the center of the arena. That seemed to make him hesitate a bit more to attack me and made his moves more predictable. Regardless of all the rest that I did, this was an important strategy.
With the move where he jumps and releases some orange "goo", I usually would dash away, and then jump straight back right next to him, to avoid the goo and strike back. With the move where he dashes at you on the floor, I would jump over him, but not strike from above, as that often pushed me upward and into an incoming Balloon. I would strike him on the floor, where I could also land multiple hits. Finally, for the move where he dashes above you, I would do an upward strike while he flies by and then hit him some more while he landed on the floor.
Finally, a word on healing: I managed to find a window for that, which is when Lost Kin is down. If there was a Balloon around, I quickly got rid of it, then began charging. Most of the time I managed to get one mask back, though on occasion the Balloons spawned far enough away that I was able to get two. I'm not sure that this boss was designed to allow you much room to heal though.
Still, nothing seemed to work. I must have had a game over dozens of times.
(Thankfully, going back to the arena takes less than ten seconds. I just jumped down to the left and dashed into it. It becomes muscle memory after a while.)
I tried all kinds of strategies. I played more defensive, more offensive, and something in between. Once I tried to hit him with the Dream Nail when he was down, but that didn't have any effect. As I tried over and over again, I kept wondering how long I would have to endure the button mashing until he gave up the ghost.
Then I began to experiment with the Descending Dark move...
...and beat him on the third try.
Well, good thing that I kept trying different moves, or else I'd be wasting another two hours some other day.
I noticed almost immediately that the Descending Dark caused him a lot more damage (made him go down more often). So, I just kept spamming it, in the middle of the arena, until he went down for good.
There are four reasons why I believe this worked:
1. The move causes enemies so much recoil, that it sometimes pushed him away from me, even while he was in the middle of an attack.
2. Also, even when he or the Balloons touched me as I executed the move, there is a brief moment when Hollow Knight turns completely dark while, and at that moment, he's completely invulnerable. There is also a brief period right before he turns dark where he is still vulnerable, so don't execute the move when any Balloon is too close to you.
3. The move has a wide hit box, which kept eliminating the encroaching Balloons.
4. My specific combo of Charms (more on that soon).
The caveat to this is that not only did I have to constantly hit him or the Balloons to recover Soul (which I usually did in two or three hits), but I also needed to wait to strike at the right time (which was pretty frequently, though when I was sweating and furiously mashing the buttons, it felt like an eternity).
Now, onto the Charms.
Every time I get a new one, I read about it, and decide whether or not to use it. This means that I have pretty much not experimented with anything other than what I have gradually been adding, simply because this combo works so well for me. Here's what I use:
Not relevant to the fight. I just really like to always be able to see where I am.
Had this since the beginning, so I'm always topped up on Soul. As I said, I was getting enough for a Descending Dark move after two or three hits.
This one took me a bit getting used to in the beginning because it just causes so much noise, but now I barely hear it. It's very useful though, especially with the likes of Lost Kin because he stays close to your vest and whenever he hits you, he gets hit back. Sometimes this happened to coincide with the last hit he needed to go down, giving me space to recover.
This one makes punishing Lost Kin that much easier because you don't need to get so close to him. Some of his attacks even allow you to hit him three times if you dodge him the right way. That one attack where he furiously swings his nail all around him, has a small enough hit box that you can strike him while he's in the animation.
Last but not least, this one ensures that I never run out of Soul to defend myself with.
Hope this helps.