I managed to bork my pam.d configs to the point that I couldn't root or sudo to gain access to reset them. In my shame, I had to create a new install USB and chroot in. Thankfully I haven't figured out drive encryption yet or I may have been SOL, I haven't the foggiest idea. This is on arch btw.
Edit 9/9/22: just use
cryptsetup open ... to decrypt the drive then follow this guide
Create and boot into an install USB
List all the available partitions
Mount the root partition - guide
mount /dev/nvme1n1p3 /mnt
Copy the pam configs from the install USB to the broken system.
cp -R /etc/pam.d /mnt/pam.d
Root into the file system
Backup the screwed-up pam configs to someplace convienty.
mv /etc/pam.d /home/User/Downloads
move the stock configs in
mv /pam.d /etc/
Reboot and remove install USB
KDE will fail to load because its pam modules aren't in the stock pam.d folder. Hopefully, you can manage to un-bork those.
F2 to exit to command line.
Login and head over to the borked files
Remove the edits from:
Move those configs back to the etc folder.
sudo cp sddm /etc/pam.d - etc
Delete the unnessesary configs used by the installer.
sudo rm vmtoolsd partimaged
Restart Xorg to login to the desktop (or restart) sudo kill -9 Xorg