So this is completely on me:
I installed Arch
I installed the plasma desktop without any additional programs
I installed sddm and told it to launch plasma desktop
I rebooted
And it did what I told it to do perfectly:
I'm now within plasma desktop.
I have no terminal emulator installed, so no way of accessing a command line from within the GUI.
Whenever I reboot, I get put back into plasma desktop.
I tried to switch to a different tty with Ctrl+Alt+F-keys but that key combo seems to be used for additional desktop sessions instead (shows me the sddm login again).
I tried creating a shell script that launches pacman and installs a terminal, but I can't, since I don't have a text editor installed.
Help!
[Edit: Solved. I was able to go to a different tty after disabling function keys]
You should still have vi installed by default. I would go the arch-chroot route, but if you can use alt+F2 to search programs, perhaps you can find vi. If yes,
!executes terminal commands. So either you can leave yourself a line in .xprofile to halt you before x loads sddm (or some other tricky thing like that) OR you could do :!pacman -SI'm a suckless-st guy myself, but you'll need a browser to get to it one way or another.
It's been a long time since I ran arch, forgot how good arch-chroot was for unfucking things I fucked.