KDE Plasma 5 is available in Void Linux.
# xbps-install -S kde5
Optionally, install KDE's baseapps package:
# xbps-install -S kde5-baseapps
Be sure to install NetworkManager for the Plasma Network applet to work and Alsa to get Audio working if required.
Remove NOX11 from /etc/pam.d/system-login (should be on the pam_ck_connector line) and reboot.
Cannot Shutdown without root
# xbps-install -S ConsoleKit2
# xbps-install -S elogind polkit-elogind
Be sure to remove console kit if installed while trying to install Elogind and vice versa.