TL;DR - dark version of PixelFun3 cursor theme.
/* Also, I'm not good at presenting things graphically, so sorry about the logo and the picture...
The other PixelFun3 themes have better pictures, so just imagine those inverted, I suppose?
Credits at the bottom. */

This is based on the PixelFun3 cursor theme originally by Kycok, with an
updated version by Ardesqa that I used for this. I also ran a fix-cursor script
that I honestly don't remember where I got it from... I wish I did so I could
credit them, but it fixes some symlinks and stuff like that which always caused
me issues.

It's basically just the PixelFun3 cursor theme inverted. I've loved the
original theme since I found it, but because I use light themes I didn't want a
light cursor as well, so I'd usually switch back to a dark cursor theme.

It seems to work fine for me in KDE on Manjaro. I don't know much about this
and I had to do some gymnastics to do what seemed simple (which means there's
probably a simpler way I could've done it) but I eventually ended up with what
I wanted.

- - -

I'm not sure I'd be able to support this very well since I really don't know
much about how this works. All I really did was find a way to open the files
provided by Ardesqa, invert them, and save them back without breaking anything.

Mainly just wanted to share it in case anyone else could use it. Was going to
just save the result onto my external hard drive and leave it at that, but
might as well put it out there if it can be of any use.

- - -

If I've miscredited anything or something like that, just let me know and I'll
take this down.

Speaking of which,
Original by Kycok: https://store.kde.org/p/999913/
Recent version by Ardesqa: https://store.kde.org/p/1190830/

And this is the script to fix symlinks that I used: https://pastebin.com/Vf8BSahP
So, if anyone knows where it came from, let me know.